JP2016163103A - Sensor device and image forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To adjust a resonance frequency in a sensor device using an LC resonance circuit.SOLUTION: A detection coil L is a planar coil that is formed on a substrate 11 and constitutes an LC resonance circuit 17. A wiring 19c is formed on the substrate 11 and connects the detection coil L and a capacitor C2 constituting the LC resonance circuit 17. An adjustment part 30a adjusts the position of a conductive member 13a so as to vary the area where the planar conductive member 13a faces the detection coil L. An adjustment part 30b adjusts the position of a conductive member 13b so as to vary the area where the planar conductive member 13b faces the wiring 19c.SELECTED DRAWING: Figure 6

Description

  The present invention relates to, for example, a sensor device used for detecting a toner density and a remaining amount of a developing unit provided in an image forming apparatus, and an image forming apparatus including the sensor device.

  An electrophotographic image forming apparatus includes a sensor device for detecting the density and remaining amount of toner in a developing unit. As such a sensor device, for example, Patent Document 1 discloses a first resonance circuit including a first coil, a second resonance circuit including a second coil magnetically coupled to the first coil, A sensor device including a capacitor constituting one resonance circuit and a shared capacitor functioning as a capacitor constituting a second resonance circuit is disclosed.

JP 2002-296236 A (Claim 1, paragraphs 0024-0026)

  The sensor device disclosed in Patent Document 1 detects the toner concentration using an LC resonance circuit. That is, this sensor device detects the toner concentration by utilizing the fact that the resonance frequency of the LC resonance circuit changes when the ratio of toner and carrier (magnetic material) in the developing unit changes.

  In a sensor device using an LC resonance circuit, the resonance frequency differs for each sensor device even with the same toner concentration, due to variations in inductance and capacitance, and variations in the mounting position of the sensor device mounted on the developing unit. For this reason, it is necessary to adjust the resonance frequency to the reference value in advance for each sensor device. In the sensor device disclosed in Patent Document 1, the resonance frequency is adjusted by adjusting the capacitance of the shared capacitor.

  An object of the present invention is to provide a sensor device using an LC resonance circuit capable of adjusting a resonance frequency and an image forming apparatus including the sensor device.

  A sensor device according to a first aspect of the present invention that achieves the above object is a substrate, a planar coil formed on the substrate, a detection coil that constitutes an LC resonance circuit, and an LC resonance circuit. A capacitor, wiring formed on the substrate and connecting the detection coil and the capacitor, a conductor member, an area where the conductor member and the detection coil face each other, and the conductor member and the wiring; An adjustment unit that adjusts the position of the conductor member such that at least one of the opposing areas can be varied.

  If there is a magnetic substance in the vicinity of the detection coil, the apparent inductance of the detection coil changes. When the inductance changes, the resonance frequency of the LC resonance circuit changes. The sensor device uses it to detect the concentration and amount of the magnetic material.

  When a current flows through the detection coil while the conductor member and the detection coil face each other, an induced current flows through the conductor member. This induced current reduces the apparent inductance of the detection coil, so that the current flowing through the detection coil increases. There is a correlation between the area where the conductor member and the detection coil face each other and the apparent inductance of the detection coil. When the area where the conductor member and the detection coil face each other increases, the apparent inductance of the detection coil decreases.

  When the conductor member and a wiring connecting the detection coil and the capacitor (hereinafter referred to as a first wiring) face each other, the apparent capacitance of the capacitor increases. There is a correlation between the area where the conductor member and the first wiring face each other and the apparent capacitance of the capacitor, and when the area where the conductor member and the first wiring face each other increases, the apparent capacitance of the capacitor increases. Become.

  The resonance frequency of the LC resonance circuit is expressed by an equation including the inductance of the detection coil and the capacitance of the capacitor. Therefore, if at least one of the area where the conductor member and the detection coil face each other and the area where the conductor member and the first wiring face each other can be made variable, the resonance frequency of the LC resonance circuit can be adjusted. it can.

  The sensor device according to the first aspect of the present invention is such that at least one of the area where the conductor member and the detection coil face each other and the area where the conductor member and the first wiring face each other are variable. An adjustment unit for adjusting the position of Therefore, the resonance frequency can be adjusted in the sensor device using the LC resonance circuit.

  In the above configuration, the conductor member includes a first conductor member and a second conductor member, and the adjustment unit is configured such that an area where the first conductor member and the detection coil face each other is variable. A first adjusting unit that adjusts the position of the first conductor member; and a second adjusting unit that adjusts the position of the second conductor member such that an area where the second conductor member and the wiring face each other is variable. And an adjustment unit.

  According to this configuration, both the area where the first conductor member and the detection coil face each other and the area where the second conductor member and the wiring (the first wiring) face each other are variable. Compared with an aspect in which one area can be varied, the resonance frequency can be adjusted more finely.

  In the above-described configuration, the wiring has a width that is thicker at a portion facing the second conductor member than at other portions.

  According to this configuration, since the area where the second conductor member and the wiring (the first wiring) face each other can be increased, the apparent fluctuation range of the capacitance of the capacitor can be increased. Thereby, it is possible to widen the adjustment range of the resonance frequency.

  In the above configuration, an insulating surface protective film that is formed on the substrate and covers the detection coil and the wiring is provided, and the adjustment unit slides the conductive member on the surface protective film, and the conductive member Adjust the position.

  According to this configuration, the conductor member can be slid while preventing the conductor member from contacting the detection coil and the wiring (the first wiring).

  An image forming apparatus according to a second aspect of the present invention includes an image carrier, an exposure unit that draws an electrostatic latent image on the image carrier, and toner on the electrostatic latent image drawn on the image carrier. And a developing unit that develops the electrostatic latent image, and the sensor device that detects a toner density or a remaining amount of the developing unit.

  Since the image forming apparatus according to the second aspect of the present invention includes the sensor device according to the first aspect of the present invention, the image forming apparatus has the same operational effects as the first aspect of the present invention.

  According to the present invention, the resonance frequency can be adjusted in the sensor device using the LC resonance circuit.

It is a top view which shows the sensor apparatus which concerns on this embodiment. In this embodiment, it is a circuit diagram which shows the circuit comprised by the detection coil L, the capacitor | condenser C1, the capacitor | condenser C2, the inverter INV1, the inverter INV2, and the resistance R. It is sectional drawing which cut | disconnected FIG. 1 along the A1-A2 line. It is a schematic diagram of the adjustment part which adjusts the position of a conductor member. It is a schematic diagram of the adjustment part after adjusting the position of a conductor member. It is a top view of the sensor apparatus after the position of the conductor member was adjusted by the adjustment part. In the modification of this embodiment, it is a top view of the sensor apparatus after the position of the conductor member was adjusted by the adjustment part. It is a block diagram which shows the structure of an image forming apparatus provided with the sensor apparatus shown in FIG.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a plan view showing a sensor device 1 according to this embodiment. The sensor device 1 includes a substrate 11, a detection coil L, a capacitor C 1, a capacitor C 2, an inverter INV 1, an inverter INV 2, a resistor R, a conductor member 13, and an adjustment unit 30. FIG. 2 is a circuit diagram illustrating a circuit configured by the detection coil L, the capacitor C1, the capacitor C2, the inverter INV1, the inverter INV2, and the resistor R in the present embodiment.

  Referring to FIG. 2, LC resonance circuit 17 is configured by detection coil L, capacitor C1, and capacitor C2. The LC resonance circuit 17 is described as a CLC type, but is not limited to this type. For example, an LC type may be used. The LC type is an LC resonance circuit 17 composed of one detection coil and one capacitor.

  One end of the detection coil L and one end of the capacitor C1 are connected, and the other end of the capacitor C1 is grounded. The other end of the detection coil L and one end of the capacitor C2 are connected, and the other end of the capacitor C2 is grounded.

  The inverters INV1 and INV2 are, for example, CMOS inverters. The output of the inverter INV1 is connected to the input of the inverter INV2. The output of the inverter INV2 is the output of the sensor device 1.

  The input of the inverter INV1 is connected to one end of the detection coil L. The output of the inverter INV1 and the input of the inverter INV2 are connected to the other end of the detection coil L via a resistor R.

  A pulse generated by the resonance of the LC resonance circuit 17 is amplified by the two-stage inverters INV1 and INV2 and output from the sensor device 1.

  The operation of the sensor device 1 will be described by taking as an example the concentration of toner contained in the two-component developer as a detection target. The two-component developer is composed of toner and a carrier made of a magnetic material. Since the carrier is a magnetic substance, the inductance of the detection coil L changes according to the concentration of the carrier in the vicinity of the detection coil L. When the inductance changes, the resonance frequency of the LC resonance circuit 17 changes. That is, in the two-component developer, when the mixing ratio of the toner and the carrier changes, the magnetic permeability of the two-component developer changes, and as a result, the resonance frequency of the LC resonance circuit 17 changes.

  When toner in the developing unit is consumed or new toner is supplied to the developing unit, the mixing ratio of the toner and the carrier changes, and the toner density and the carrier density change. If the toner density is high, the carrier density is low, and if the toner density is low, the carrier density is high. The image forming apparatus stores in advance a table indicating the relationship between the toner density and the resonance frequency, and obtains the toner density from the pulse frequency (resonance frequency) output from the sensor device 1.

  Referring to FIG. 1, substrate 11 is an insulating substrate, and detection coil L and wiring 19 are formed on the main surface of substrate 11 by patterning. The capacitor C1, the capacitor C2, the resistor R, the inverter INV1, and the inverter INV2 are externally attached on the main surface of the substrate 11. The detection coil L, the capacitor C1, the capacitor C2, the resistor R, the inverter INV1, and the inverter INV2 are connected by the wiring 19, and constitute the circuit shown in FIG.

  FIG. 3 is a cross-sectional view of FIG. 1 cut along the line A1-A2. With reference to FIGS. 1 and 3, wiring 19 a is formed directly on the main surface of substrate 11. The main surface of the substrate 11 and the wiring 19 a are covered with an interlayer insulating film 21. On the interlayer insulating film 21, wirings 19 (for example, wiring 19b and wiring 19c) other than the detection coil L and the wiring 19a are formed.

  The detection coil L is a spiral planar coil. The other end of the detection coil L is located at the center of the spiral and is connected to one end of the wiring 19 a by a plug 27 embedded in the interlayer insulating film 21. The other end of the wiring 19 a is connected to a wiring 19 b formed on the interlayer insulating film 21 by a plug 25 embedded in the interlayer insulating film 21.

  The other end of the detection coil L is connected to the resistor R through the wiring 19a and the wiring 19b, and is connected to the capacitor C2 through the wiring 19a, the wiring 19b, and the wiring 19c.

  The wiring 19 other than the detection coil L and the wiring 19 a is covered with an insulating surface protective film 23.

  Referring to FIG. 1, the sensor device 1 further includes a power supply terminal Vcc, a ground terminal GND1, a ground terminal GND2, and an output terminal OP provided on the side of the substrate 11. Electric power is supplied to the sensor device 1 via the power supply terminal Vcc. The capacitor C1 is grounded via the ground terminal GND1. The capacitor C2 is grounded via the ground terminal GND2. The pulse output from the inverter INV2 is output to the outside of the sensor device 1 via the output terminal OP.

  The two conductor members 13 are disposed on the surface protective film 23 shown in FIG. When distinguishing these conductor members 13, they are described as conductor members 13a and 13b. The conductor member 13 is a plate-like member having a predetermined shape (in this embodiment, an isosceles trapezoid). The material of the conductor member 13 is a metal having conductivity such as copper, aluminum, or iron.

  The conductor member 13 is slidable on the surface protective film 23 along the arrow B direction and the arrow C direction opposite thereto, whereby the position of the conductor member 13 is adjusted. The arrow B direction is the forward direction of the conductor member 13. An arrow C direction is a backward direction of the conductor member 13.

  The position of the conductor member 13 is adjusted by the adjusting unit 30. There are two adjustment units 30, and when these are distinguished, they are referred to as adjustment units 30a and 30b.

  FIG. 4 is a schematic diagram of the adjusting unit 30 that adjusts the position of the conductor member 13. The adjustment unit 30 includes a knob portion 31, a female screw portion 33, a compression coil spring 35, and a holding portion 37.

  The female screw portion 33 is attached to one side portion of the substrate 11. The holding portion 37 is disposed so as to face the female screw portion 33 and is attached to the side portion of the substrate 11 facing the one side portion.

  The conductor member 13 has upper and lower trapezoidal shapes that are bent at about 90 degrees to form upright portions 39 and 41, respectively.

  One end of the compression coil spring 35 is fixed to the upright portion 41, and the other end is fixed to the holding portion 37.

  The knob portion 31 has a male screw portion 43, the male screw portion 43 is fitted into the female screw portion 33, and the tip thereof is in contact with the upright portion 39. When the knob portion 31 is rotated clockwise, the knob portion 31 moves in the direction of arrow B, the tip of the male screw portion 43 presses the upright portion 39, and the conductor member 13 moves to the compression coil spring 35 as shown in FIG. Slide against arrow B.

  When the knob portion 31 is turned counterclockwise, the knob portion 31 moves in the direction of arrow C. As shown in FIG. 4, the conductor member 13 is pushed by the compression coil spring 35, and the conductor member 13 slides in the arrow C direction. To do.

  FIG. 6 is a plan view of the sensor device 1 after the position of the conductor member 13 is adjusted by the adjusting unit 30. As described above, when the adjustment unit 30a is rotated clockwise, the conductor member 13a slides in the direction of arrow B with the upper base of the trapezoidal shape as a head, and partially faces the detection coil L. When the amount of movement of the conductor member 13a in the direction of arrow B is increased, the facing area between the conductor member 13a and the detection coil L increases.

  When the adjustment unit 30b is turned clockwise, the conductor member 13b slides in the arrow B direction with the upper base of the trapezoidal shape as the head, and partially faces the wiring 19c. Increasing the amount of movement of the conductor member 13b in the direction of arrow B increases the facing area between the conductor member 13b and the wiring 19c. The wiring 19c is a part of the wiring 19 that connects the other end (the center of the spiral) of the detection coil L and the capacitor C2.

  The main effects of this embodiment will be described. Referring to FIG. 6, when there is a magnetic material in the vicinity of detection coil L, the apparent inductance of detection coil L changes. When the inductance changes, the resonance frequency of the LC resonance circuit 17 changes. The sensor apparatus 1 detects the density | concentration and quantity of a magnetic body using it.

  When a current flows through the detection coil L with the conductor member 13a and the detection coil L facing each other, an induced current flows through the conductor member 13a. This induced current decreases the apparent inductance of the detection coil L, so that the current flowing through the detection coil L increases. The area where the conductor member 13a and the detection coil L face each other and the apparent inductance of the detection coil L have a correlation, and when the area where the conductor member 13a and the detection coil L face each other increases, the appearance of the detection coil L becomes larger. The inductance becomes smaller.

  When the conductor member 13b and the wiring 19c that connects the detection coil L and the capacitor C2 face each other, the apparent capacitance of the capacitor C2 increases. There is a correlation between the area where the conductor member 13b and the wiring 19c face each other and the apparent capacitance of the capacitor C2, and when the area where the conductor member 13b and the wiring 19c face each other increases, the apparent capacitance of the capacitor C2 increases. Become.

  The resonance frequency of the LC resonance circuit 17 is expressed by an equation including the inductance of the coil and the capacitance of the capacitor. In the CLC type resonance circuit, the resonance frequency F is expressed by the following equation.

  Therefore, if at least one of the area where the conductor member 13a and the detection coil L face each other and the area where the conductor member 13b and the wiring 19c face each other is variable, the resonance frequency of the LC resonance circuit 17 is adjusted. be able to. When the conductor member 13a and the detection coil L face each other, the apparent inductance of the detection coil L is relatively greatly reduced. When the conductor member 13b and the wiring 19c face each other, the appearance of the capacitor C2 The capacitance increases relatively small.

  According to the sensor device 1 according to the present embodiment, the adjustment unit 30a that adjusts the position of the conductor member 13a so that the area where the conductor member 13a and the detection coil L face each other is variable, and the conductor member 13b and the wiring 19c are provided. An adjustment unit 30b is provided for adjusting the position of the conductor member 13b so that the opposing areas can be varied. Therefore, in the sensor device 1 using the LC resonance circuit 17, the resonance frequency can be adjusted.

  In addition, according to the present embodiment, both the area where the conductor member 13a and the detection coil L face each other and the area where the conductor member 13b and the wiring 19c face each other can be changed, so that one of the areas can be changed. Compared with the embodiment, the resonance frequency can be adjusted more finely.

  With reference to FIGS. 4 and 5, according to the present embodiment, the adjusting unit 30 adjusts the position of the conductor member 13 by sliding the conductor member 13 on the surface protective film 23. Therefore, the conductor member 13 can be slid while preventing the conductor member 13 from coming into contact with the detection coil L and the wiring 19c.

  A modification of this embodiment will be described. FIG. 7 is a plan view of the sensor device 3 after the position of the conductor member 13 is adjusted by the adjustment unit 30 in the modification of the present embodiment. The sensor device 3 according to the modified example is different from the sensor device 1 according to the present embodiment in the width of the wiring 19c, and the width of the wiring 19c is larger than the width of the other wirings 19. That is, as for the wiring 19, the part which opposes the conductor member 13b has a thick width compared with another part.

  According to the modification, since the area where the conductor member 13b and the wiring 19c face each other can be increased, the apparent capacitance fluctuation range of the capacitor C2 can be increased. Thereby, it is possible to widen the adjustment range of the resonance frequency.

  The sensor device 1 according to this embodiment and the sensor device 3 according to the modification can be mounted on an image forming apparatus. This will be described using the sensor device 1 as an example. FIG. 8 is a block diagram illustrating a configuration of the image forming apparatus 5 in which the sensor device 1 according to the present embodiment is mounted.

  The image forming apparatus 5 will be described by taking a digital multifunction machine having a copy, printer, scanner, and facsimile function as an example. The image forming apparatus 5 may be an apparatus having a function of printing an image, and is not limited to a digital multifunction peripheral. For example, the printer may be the image forming apparatus 5. The image forming apparatus 5 includes a printing unit 100, a document reading unit 200, a document feeding unit 300, an operation unit 400, a control unit 500, a communication unit 600, and a toner container 700.

  When a single document is placed on the document placement unit provided in the document feed unit 300, the document feed unit 300 sends the document to the document reading unit 200, and a plurality of documents are placed on the document placement unit. When an original is placed, a plurality of originals are continuously sent to the original reading unit 200.

  The document reading unit 200 reads a document placed on a document table or a document fed from the document feeding unit 300 and outputs image data of the document.

  The printing unit 100 includes a paper storage unit 101, an image forming unit 103, and a fixing unit 105. The sheet storage unit 101 can store a bundle of sheets. In the stored bundle of sheets, the uppermost sheet is sent out toward a sheet conveyance path (not shown) by driving a pickup roller (not shown). The sheet is conveyed to the image forming unit 103 through the sheet conveyance path.

  The image forming unit 103 forms a toner image on the conveyed paper. The image forming unit 103 includes a photosensitive drum 113 (an example of an image carrier), an exposure unit 115, a developing unit 117, and a transfer unit 119. The exposure unit 115 generates light modulated according to image data (image data output from the document reading unit 200, image data transmitted from a personal computer, image data received by facsimile, etc.), and is uniformly charged. Irradiate the circumferential surface of the photosensitive drum 113. As a result, an electrostatic latent image corresponding to the image data is drawn on the peripheral surface of the photosensitive drum 113. In this state, toner is supplied to the peripheral surface of the photosensitive drum 113 from the developing unit 117, so that a toner image corresponding to the image data is formed on the peripheral surface. This toner image is transferred by the transfer unit 119 to the sheet conveyed from the sheet storage unit 101 described above.

  The sheet on which the toner image is transferred is sent to the fixing unit 105. In the fixing unit 105, heat and pressure are applied to the toner image and the paper, and the toner image is fixed to the paper. The paper is discharged to a paper discharge tray (not shown).

  A two-component developer is accommodated in the developer accommodating portion 121 of the developing portion 117. A sensor device 1 shown in FIG. 1 is attached to the outer surface of the bottom wall portion of the developer accommodating portion 121. The sensor device 1 detects the toner concentration in the two-component developer stored in the developer storage unit 121.

  When the toner in the developer storage unit 121 is consumed and the sensor device 1 detects that the toner concentration in the two-component developer has decreased, the control unit 500 provides a toner supply mechanism provided in the toner container 700. Is activated. As a result, the toner is supplied from the toner container 700 to the developer accommodating portion 121.

  The operation unit 400 includes an operation key unit 401 and a display unit 403. The display unit 403 has a touch panel function, and displays a screen including soft keys. The user operates the soft key while viewing the screen to make settings necessary for executing functions such as copying.

  The operation key unit 401 is provided with operation keys including hard keys. The operation key is, for example, a function switching key for switching between a start key, a numeric keypad, a reset key, a copy, a printer, a scanner, and a facsimile.

  The control unit 500 includes a CPU, a ROM, and a RAM. The CPU executes control necessary for operating the image forming apparatus 5 on the above-described components (for example, the printing unit 100) of the image forming apparatus 5. The ROM stores software necessary for controlling the operation of the image forming apparatus 5. The RAM is used for temporary storage of data generated during execution of software, storage of application software, and the like.

  The communication unit 600 includes a facsimile communication unit 601 and a network I / F unit 603. The facsimile communication unit 601 includes an NCU (Network Control Unit) that controls connection of a telephone line with a destination facsimile and a modulation / demodulation circuit that modulates / demodulates a signal for facsimile communication. The facsimile communication unit 601 is connected to the telephone line 605.

  The network I / F unit 603 is connected to a LAN (Local Area Network) 607. A network I / F unit 603 is a communication interface circuit for executing communication with a personal computer connected to the LAN 607.

DESCRIPTION OF SYMBOLS 1,3 Sensor apparatus 5 Image forming apparatus 11 Board | substrate 13 Conductor member 13a Conductor member (an example of 1st conductor member)
13b Conductor member (example of second conductor member)
17 LC resonance circuit 19 wiring 19c wiring (an example of wiring for connecting the detection coil and the capacitor)
23 surface protective film 30 adjustment part 30a adjustment part (an example of a 1st adjustment part)
30b adjuster (an example of a second adjuster)
113 Photosensitive drum (an example of an image carrier)
115 Exposure unit 117 Development unit L Detection coils C1, C2 Condenser

Claims (5)

A substrate,
A planar coil formed on the substrate, and a detection coil constituting an LC resonance circuit;
A capacitor constituting the LC resonance circuit;
Wiring formed on the substrate and connecting the detection coil and the capacitor;
A conductor member;
An adjustment unit that adjusts the position of the conductor member such that at least one of an area where the conductor member and the detection coil face each other and an area where the conductor member and the wiring face each other are variable. Sensor device. The conductor member includes a first conductor member and a second conductor member,
The adjustment unit includes a first adjustment unit that adjusts a position of the first conductor member so that an area in which the first conductor member and the detection coil face each other is variable, and the second conductor member; The sensor device according to claim 1, further comprising: a second adjustment unit that adjusts a position of the second conductor member such that an area facing the wiring is variable.   The sensor device according to claim 2, wherein a portion of the wiring facing the second conductor member has a larger width than other portions. An insulating surface protection film formed on the substrate and covering the detection coil and the wiring;
The sensor device according to claim 1, wherein the adjustment unit adjusts a position of the conductor member by sliding the conductor member on the surface protective film. An image carrier;
An exposure unit for drawing an electrostatic latent image on the image carrier;
A developing unit that supplies toner to the electrostatic latent image drawn on the image carrier to develop the electrostatic latent image;
An image forming apparatus comprising: the sensor device according to claim 1, wherein the sensor device detects a toner density or a remaining amount of the developing unit.

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