JP2014215512A - Image formation device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image formation device capable of detecting that a waste toner storage unit is filled, while suppressing erroneous detection, by using a simple configuration.SOLUTION: The image formation device has a magnet 71 and a magnetic sensor 72 disposed at a prescribed height lower than an opening 393 and on both sides of an upper end section 392 of a waste toner storage unit 39 in which the opening 393 is formed in the upper end section 392, the opening 393 being provided for receiving a magnetic toner containing magnetic substance discharged from an image formation unit for forming an image by using the magnetic toner. Whether the waste toner storage unit 39 is full or not is determined depending on a magnetic flux density detected by the magnetic sensor 72.

Description

  The present invention relates to an image forming apparatus having a full detection function of a waste toner storage unit that stores waste toner discharged from an image forming unit.

  In general, an image forming apparatus having a function of detecting a fullness of a waste toner storage unit that stores waste toner discharged from the image forming unit is known. For example, the amount of waste toner in the waste toner storage unit is detected according to the detection result of an optical sensor having a light emitting unit and a light receiving unit disposed on both sides of the waste toner storage unit. However, if an optical sensor is used, there is a possibility that erroneous detection may occur due to ambient light or toner contamination on the inner wall of the waste toner storage unit.

  On the other hand, as a configuration that does not use an optical sensor, a technique that uses a support member that is displaced in the vertical direction according to the amount of toner and a magnetic sensor that detects the position of the support member is also known (see, for example, Patent Document 1). ).

JP 2012-155279 A

  However, if a support member that is displaced in the vertical direction is provided in the waste toner storage unit, the configuration of the waste toner storage unit becomes complicated, and the support member may not be displaced normally.

  SUMMARY OF THE INVENTION An object of the present invention is to provide an image forming apparatus capable of detecting fullness of a waste toner container with a simple configuration while preventing erroneous detection.

  The image forming apparatus according to the present invention includes an image forming unit, a waste toner storage unit, a magnet, a magnetic sensor, and a fullness detection unit. The image forming unit forms an image using a magnetic toner containing a magnetic material. In the waste toner storage portion, an opening for receiving the magnetic toner discharged from the image forming portion is formed at an upper end portion. The magnet and the magnetic sensor are arranged on both sides of the upper end at a predetermined height lower than the opening. The magnetic sensor detects a magnetic flux density of lines of magnetic force generated by the magnet. The full detection means determines whether the waste toner container is full according to the magnetic flux density detected by the magnetic sensor.

  According to the present invention, an image forming apparatus capable of detecting the fullness of the waste toner container with a simple configuration while preventing erroneous detection is realized.

1 is a schematic cross-sectional view showing a schematic configuration of a multifunction machine according to an embodiment of the present invention. FIG. 5 is a diagram for explaining a full detection method for a waste toner storage unit in the multifunction peripheral according to the embodiment of the present invention. FIG. 5 is a diagram for explaining a full detection method for a waste toner storage unit in the multifunction peripheral according to the embodiment of the present invention. FIG. 10 is a diagram for explaining another example of a full detection method for a waste toner storage unit in the multifunction peripheral according to the embodiment of the present invention.

  Embodiments of the present invention will be described below with reference to the accompanying drawings for understanding of the present invention. In addition, the following embodiment is an example which actualized this invention, Comprising: The thing of the character which limits the technical scope of this invention is not.

<Schematic configuration of MFP 10>
First, a schematic configuration of a multifunction machine 10 according to an embodiment of the present invention will be described with reference to FIG.

  As shown in FIG. 1, the multifunction machine 10 includes an ADF 1, an image reading unit 2, an image forming unit 3, a paper feed cassette 4, a control unit 5, an operation display unit 6, a toner detection unit 7, and the like. The multifunction machine 10 is merely an example of the image forming apparatus of the present invention, and a printer, a copier, a facsimile machine, and the like also correspond to the image forming apparatus according to the present invention.

  The ADF 1 drives each of the transport rollers 12 by a motor (not shown), and transports the document set on the document placement unit 11 to the paper discharge tray 13 through the image reading position by the image reading unit 2. This is an automatic document feeder.

  The image reading unit 2 is an image reading unit including a document table 21, a light source unit 22, mirrors 23 and 24, an optical lens 25, a CCD (Charge Coupled Device) 26, and the like. The document table 21 is a document placement unit provided on the upper surface of the image reading unit 2. The reading unit 22 includes an LED light source 221 and a mirror 222, and is movable in a sub-scanning direction (left and right direction in FIG. 1) by a motor (not shown). The LED light source 221 includes a number of white LEDs arranged along the main scanning direction (the depth direction in FIG. 1). The mirror 222 reflects the light emitted from the LED light source 221 and reflected by the surface of the document at the reading position on the document table 21 toward the mirror 23. The light reflected by the mirror 222 is guided to the optical lens 25 by the mirrors 23 and 24. The optical lens 25 collects incident light and makes it incident on the CCD 26. The CCD 26 includes a photoelectric conversion element that inputs an electrical signal corresponding to the amount of light incident from the optical lens 25 to the control unit 5 as image data of the document.

  The image forming unit 3 performs an image forming process (printing process) based on image data read by the image reading unit 2 or image data input from an information processing apparatus such as an external personal computer. This is an image forming unit of the type. Specifically, the image forming unit 3 includes a photosensitive drum 31, a charging device 32, an exposure device (LSU) 33, a developing device 34, a transfer roller 35, a cleaning device 36, a fixing roller 37, a pressure roller 38, and a disposal. A toner storage unit 39 and the like are provided. In the image forming unit 3, an image forming process for forming an image using a magnetic toner containing a magnetic material on a sheet such as paper supplied from the paper feeding cassette 4 is executed in the following procedure.

  First, the photosensitive drum 31 is uniformly charged to a predetermined potential by the charging device 32. Next, the exposure device 33 irradiates the surface of the photosensitive drum 31 with light based on image data. As a result, an electrostatic latent image corresponding to the image data is formed on the surface of the photosensitive drum 31. The electrostatic latent image on the photosensitive drum 31 is developed (visualized) with magnetic toner by the developing device 34. The developing device 34 is supplied with magnetic toner from a toner container 34 </ b> A that can be attached to and detached from the image forming unit 3. Subsequently, the toner image formed on the photosensitive drum 31 is transferred to a sheet by the transfer roller 35. Thereafter, the toner image transferred to the sheet is heated and fixed by the fixing roller 37 when the sheet passes between the fixing roller 37 and the pressure roller 38.

  On the other hand, the magnetic toner remaining on the surface of the photosensitive drum 31 after the image forming process by the image forming unit 3 is removed by the cleaning device 36. The magnetic toner removed by the cleaning device 36 is discharged as waste toner and is stored in the waste toner storage unit 39. Specifically, the magnetic toner discharged from the cleaning device 36 is transported to the waste toner container 39 by driving a transport member such as a spiral member in a toner discharge path (not shown).

  The control unit 5 is a computer having control devices such as a CPU, ROM, RAM, and EEPROM. The CPU is a processor that executes various arithmetic processes. The ROM is a non-volatile storage unit in which information such as a control program for causing the CPU to execute various processes is stored in advance. The RAM is volatile storage means, and the EEPROM is nonvolatile storage means. The RAM and the EEPROM are used as a temporary storage memory (working area) for various processes executed by the CPU.

  Then, the control unit 5 performs overall control of the multifunction machine 10 by executing various control programs stored in advance in the ROM by the CPU. The control unit 5 may be an electronic circuit such as an integrated circuit (ASIC, DSP), and the image forming unit 3 is separate from the main control unit that controls the multifunction device 10 in an integrated manner. The engine control part provided in the above may be sufficient.

  The operation display unit 6 includes a display unit such as a liquid crystal display that displays various types of information in accordance with control instructions from the control unit 5, and hard keys that input various types of information to the control unit 5 in response to user operations. Or an operation unit such as a touch panel.

  The toner detection unit 7 includes a magnet 71 and a magnetic sensor 72 that are used to detect the fullness of the waste toner storage unit 39. The magnet 71 and the magnetic sensor 72 are disposed on a support portion (not shown) that supports the waste toner storage portion 39. For example, the support portion (not shown) is a part of the main body frame of the multi-function device 10, and the waste toner storage portion 39 is fixed to the main body frame of the multi-function device 10 or is swingably mounted. Yes. The support unit (not shown) may be a housing such as the image forming unit 3 or the cleaning device 36. Further, the waste toner container 39 may be supported in a state of being suspended by the magnetic toner discharge port of the cleaning device 36.

  FIG. 2 is a schematic diagram showing a schematic configuration of the toner detection unit 7 and the waste toner storage unit 39. As shown in FIG. 2, the waste toner container 39 is a resin container having a main body 391 for storing the magnetic toner T and an upper end 392 provided on the upper part of the main body 391. It can be attached to and detached from the multifunction machine 10. An opening 393 for receiving the magnetic toner T discharged from the cleaning device 36 by the screw member (not shown) is formed on the upper surface of the upper end 392. Note that the diameter of the horizontal section of the upper end 392 is smaller than the diameter of the horizontal section of the main body 391, and a large amount of the magnetic toner T can be accommodated in the main body 391.

  The magnet 71 and the magnetic sensor 72 are disposed on both sides of the upper end 392 at a predetermined height lower than the opening 393. That is, the detection target position of the magnetic sensor 72 is set to a position lower than the opening 393, and the magnetic sensor 72 is configured so that the magnetic toner T in the waste toner container 39 is opened as described later. Used to detect full condition before full to 393.

  The magnet 71 is a permanent magnet, and is arranged in the order of N pole and S pole as viewed from the upper end 392 side. In other words, the magnet 71 is arranged so that the polarity close to the upper end 392 is an N pole. As a result, magnetic lines of force are generated by the magnet 71 in the direction from the magnet 71 toward the magnetic sensor 72 at the upper end 392. Further, since the magnet 71 is a permanent magnet, it is not necessary to wire the magnet 71, and only the wiring to the magnetic sensor 72 is required, so the number of wires can be reduced.

  The magnetic sensor 72 includes a Hall element that detects a magnetic flux density (magnetic field) of a magnetic force line generated by the magnet 71 and directed in a direction from the magnet 71 toward the magnetic sensor 72, and is detected according to the magnitude of the magnetic flux density. A signal (voltage level) is input to the control unit 5. As described above, the use of the Hall element capable of detecting the magnetic flux density of the magnetic field lines in one direction as the magnetic sensor 72 can realize the full detection function of the waste toner container 39 with an inexpensive configuration.

  The magnetic sensor 72 is not limited to one using a Hall element as long as it can detect the magnetic flux density of the lines of magnetic force generated by the magnet 71. The magnetic sensor 72 is configured to detect both the magnetic flux lines generated in the direction from the magnet 71 toward the magnetic sensor 72 and the magnetic lines generated in the direction from the magnetic sensor 72 toward the magnet 71. It may be.

  Then, the control unit 5 determines whether the waste toner storage unit 39 is full according to the magnetic flux density detected by the magnetic sensor 72. The said control part 5 when performing the process which concerns here is an example of a full detection means.

  Specifically, when the magnetic toner T is filled up to between the magnet 71 and the magnetic sensor 72, the magnetic sensor 72 has a magnetic flux density that is equal to or higher than a preset threshold value. When the magnetic toner T is not filled between the magnet 71 and the magnetic sensor 72, the magnetic flux density detected by the magnetic sensor 72 is arranged in a positional relationship that is less than the threshold value. The control unit 5 determines that the waste toner storage unit 39 is full when the magnetic flux density detected by the magnetic sensor 72 is greater than or equal to the threshold value.

  Hereinafter, a full detection method for the waste toner storage unit 39 using the toner detection unit 7 will be described with reference to FIGS. 2 and 3.

  First, consider the case where the magnetic toner T in the waste toner container 39 does not reach the upper end 392 as shown in FIG. In this case, the magnetic flux density of the magnetic force lines reaching the magnetic sensor 72 from the magnet 71 via air is small. In the multi-function device 10, the magnet 71 and the magnetic sensor 72 are arranged in a positional relationship where the magnetic flux density detected by the magnetic sensor 72 at this time is less than the threshold value. Therefore, in this state, the magnetic flux density detected by the magnetic sensor 72 is less than the threshold value, and the control unit 5 determines that the waste toner storage unit 39 is not full.

  Next, consider a case where the magnetic toner T in the waste toner container 39 reaches the upper end 392 and is filled between the magnet 71 and the magnetic sensor 72 as shown in FIG. In this case, the magnetic toner T interposed between the magnet 71 and the magnetic sensor 72 acts as a yoke. For this reason, the lines of magnetic force reaching the magnetic sensor 72 from the magnet 71 increase, and the magnetic flux density detected by the magnetic sensor 72 increases. In the multi function device 10, the magnet 71 and the magnetic sensor 72 are arranged in such a positional relationship that the magnetic flux density detected by the magnetic sensor 72 at this time is equal to or greater than the threshold value. Therefore, in this state, the magnetic flux density detected by the magnetic sensor 72 is equal to or higher than the threshold value, and the control unit 5 determines that the waste toner storage unit 39 is full.

  Note that when the control unit 5 determines that the waste toner storage unit 39 is full, for example, it is possible to display an error signal or a replacement notification indicating the fact on the operation display unit 6. Accordingly, it is possible to prompt the user to discard the magnetic toner in the waste toner storage unit 39 or replace the waste toner storage unit 39. In addition, when it is determined that the waste toner storage unit 39 is full, the control unit 5 may prohibit execution of the image forming process by the image forming unit 3. This prevents the magnetic toner from overflowing from the waste toner storage unit 39 or the magnetic toner from clogging the toner discharge path (not shown) following the image forming unit 3.

  As described above, in the multifunction machine 10, the control unit 5 determines whether the waste toner storage unit 39 is full using the magnet 71 and the magnetic sensor 72. For this reason, as in the case of using a transmissive optical sensor, erroneous detection due to ambient light or contamination of the waste toner container 39 is prevented. In addition, since there is no need to provide the waste toner container 39 with a support member that is displaced in the vertical direction according to the amount of toner as in the prior art described above, the configuration of the multifunction machine 10 can be simplified. Occurrence of a full detection failure of the waste toner storage unit 39 due to the malfunction of the movable member is also prevented. Further, in the case where an optical sensor is used to detect the fullness of the waste toner storage unit 39, it is necessary to wire each of the light emitting unit and the light receiving unit. However, in the multifunction machine 10, only the magnetic sensor 72 needs to be wired. It is also possible to reduce the number of wires. It is also possible to use an electromagnet as the magnet 71 without considering the reduction in the number of wires.

[Other Embodiments]
FIG. 4 is a view showing another example of the toner detection unit 7. In the example shown in FIG. 4, the magnets 71 are arranged in the order of S poles and N poles as viewed from the upper end 392 side. That is, the magnet 71 is arranged so that the polarity close to the upper end 392 becomes the S pole. Thereby, in the upper end portion 392, the direction of the lines of magnetic force generated by the magnet 71 is opposite to the configuration of the toner detecting unit 7 shown in FIG. The multifunction device 10 is provided with a magnetic sensor 73 for detecting the magnetic flux density of the magnetic force lines in the direction toward the magnet 71 (the right direction in FIG. 4) instead of the magnetic sensor 72. Similar to the magnetic sensor 72, the magnetic sensor 73 includes a Hall element that detects the magnetic flux density of the magnetic field lines, and inputs a detection signal corresponding to the magnitude of the magnetic flux density to the control unit 5. Also in the multi-function device 10 configured as described above, the magnetic lines of force increase when the magnetic toner T is filled between the magnet 71 and the magnetic sensor 73, and the magnetic sensor 73 has a magnetic flux density equal to or higher than the threshold. Detected. Therefore, the control unit 5 can determine whether or not the waste toner storage unit 39 is full using the magnet 71 and the magnetic sensor 73.

  The magnetic sensor 73 may be one in which the magnetic sensor 72 is simply arranged in the reverse state. The magnetic sensor 73 is configured to detect both the magnetic flux lines generated in the direction from the magnetic sensor 73 toward the magnet 71 and the magnetic lines generated in the direction from the magnet 71 toward the magnetic sensor 73. It may be. The magnetic sensor 72 or the magnetic sensor 73 used in the toner detection unit 7 does not need to detect the direction of the magnetic force lines generated by the magnet 71, and can detect the magnetic flux density of the magnetic force lines generated by the magnet 71. If it is. For example, the magnetic sensor 72 or the magnetic sensor 73 may be a sensor that detects magnetic flux density using a magnetic impedance element or a Faraday element. As long as the magnetic sensor 72 detects the magnetic flux density regardless of the direction of the magnetic flux density, the same magnetic sensor 72 can be used regardless of the direction of the magnet 71.

  The magnet 71 may be provided in the waste toner storage unit 39. Accordingly, for example, the control unit 5 changes the attachment / detachment state of the waste toner storage unit 39 according to a change in magnetic flux density detected by the magnetic sensor 72 when the waste toner storage unit 39 is attached / detached to / from the multifunction machine 10. It becomes possible to detect. That is, the magnetic sensor 72 can be used for both detection of attachment / detachment of the waste toner container 39 and full detection of the waste toner container 39.

  Further, when the waste toner container 39 is attached to the multifunction machine 10 in the front and back directions, there is a possibility that the front and back surfaces of the waste toner container 39 are attached in the reverse state. On the other hand, when the waste toner container 39 is correctly installed, the magnet 71 is built in the waste toner container 39 so that the magnet 71 and the magnetic sensor 72 are positioned to sandwich the upper end 392. A possible configuration is conceivable. In this case, if the magnetic sensor 72 can detect the magnetic flux density of bidirectional magnetic lines of force, the magnet 71 comes close to the magnetic sensor 72 when the waste toner container 39 is mounted in the reverse direction. . Therefore, the waste toner container is provided on the condition that the control unit 5 changes the magnetic flux density detected by the magnetic sensor 72 when the image forming process by the image forming unit 3 is not performed. It is conceivable to detect an abnormality in the wearing state of 39.

10: MFP 1: ADF
2: Image reading unit 3: Image forming unit 31: Photosensitive drum 32: Charging device 33: Exposure device 34: Developing device 35: Transfer roller 36: Cleaning device 37: Fixing roller 38: Pressure roller 39: Waste toner storage unit 391: Storage unit 392: Upper end 393: Opening 4: Paper cassette 5: Control unit 6: Operation display unit 7: Toner detection unit 71: Magnet 72: Magnetic sensor 73: Magnetic sensor

Claims (5)

An image forming unit that forms an image using a magnetic toner containing a magnetic material;
A waste toner storage portion in which an opening for receiving the magnetic toner discharged from the image forming portion is formed at an upper end;
A magnet disposed on both sides of the upper end at a predetermined height lower than the opening, and a magnetic sensor for detecting a magnetic flux density of magnetic lines of force generated by the magnet;
Full detection means for determining whether the waste toner container is full according to the magnetic flux density detected by the magnetic sensor;
An image forming apparatus comprising: When the magnetic toner is filled between the magnet and the magnetic sensor, the magnetic sensor detects a magnetic flux density equal to or higher than a preset threshold value between the magnet and the magnetic sensor. When the magnetic toner is not filled up to, the magnetic flux density detected by the magnetic sensor is arranged in a positional relationship that is less than the threshold value,
The image forming apparatus according to claim 1, wherein the fullness detection unit determines that the waste toner container is full when the magnetic sensor detects a magnetic flux density equal to or higher than the threshold value.   The image forming apparatus according to claim 1, wherein the magnet is a permanent magnet.   The image forming apparatus according to claim 1, wherein the upper end portion is provided on an upper portion of a main body portion of the waste toner storage portion that stores the magnetic toner, and has a smaller horizontal cross-sectional diameter than the main body portion. . The magnet is arranged so that the polarity close to the upper end is an N pole,
The image forming apparatus according to claim 1, wherein the magnetic sensor includes a Hall element that detects a magnetic flux density of a magnetic force line in a direction from the magnet toward the magnetic sensor.

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