JP2021196400A - Detection system, toner storage device, and image forming apparatus - Google Patents

Abstract

To accurately detect the state of a filter.SOLUTION: A detection system 35 is provided with a filter 36 that can collect toner (powder), a counter electrode 37 that is installed on the filter 36, and a detection unit 62 (detection means) that detects a change of an electric field formed on the counter electrode 37.SELECTED DRAWING: Figure 2

Description

The present invention relates to a detection system for detecting the state of a filter, a toner accommodating device including the detection system, and an image forming device such as a copying machine, a printer, a facsimile, or a combination machine thereof.

Conventionally, in an image forming apparatus such as a copier or a printer, a technique of installing a filter for collecting powder such as toner floating in the apparatus and discharging only air to the outside of the apparatus has been known (. For example, see Patent Document 1).

On the other hand, Patent Document 1 discloses a technique of detecting a state in which a filter is clogged with dust such as toner by a wind speed sensor or a magnetic sensor installed in the vicinity of the filter.

Conventional technology has not been able to accurately detect the state in which the filter is clogged with powder.
In particular, the technique of Patent Document 1 causes variations in the detection results of the wind speed sensor due to obstacles (for example, walls, etc.) installed around the image forming apparatus, and accurately detects the state of the filter. In some cases, it could not be done and false positives were made.

The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide a detection system, a toner accommodating device, and an image forming apparatus capable of accurately detecting the state of a filter.

The detection system in the present invention includes a filter capable of collecting powder, a counter electrode installed on the filter, and a detection means for detecting a change in an electric field formed on the counter electrode. ..

According to the present invention, it is possible to provide a detection system, a toner accommodating device, and an image forming apparatus capable of accurately detecting the state of a filter.

It is an overall block diagram which shows the image forming apparatus in embodiment of this invention. It is a block diagram which shows the collecting device which collects the floating toner and the paper dust together with ozone. It is the figure which looked at the collecting device of FIG. 2 from above. It is a perspective view which shows the detection system. (A) an enlarged front view showing a part of the upstream electrode plate, and (B) an enlarged front view showing a part of the downstream electrode plate. It is a graph which shows the relationship between the toner stain amount of a filter, and the change amount of the capacitance of a counter electrode. It is an enlarged view which shows the main part of the detection system as a modification 1. FIG. It is a figure which shows the collecting apparatus as a modification 2. It is a figure which shows the collecting apparatus as a modification 3. FIG.

Hereinafter, embodiments for carrying out the present invention will be described in detail with reference to the drawings. In each figure, the same or corresponding parts are designated by the same reference numerals, and the duplicated description thereof will be appropriately simplified or omitted.

First, FIG. 1 describes the overall configuration and operation of the image forming apparatus 1.
In FIG. 1, 1 is a copying machine as an image forming apparatus, 2 is a document reading unit that optically reads image information of a document D, and 3 is a photoconductor that emits exposure light L based on the image information read by the document reading unit 2. The exposed part to irradiate on the drum 5 is shown.
Further, 4 is a developing device for developing a latent image formed on the photoconductor drum 5 to form a toner image (image), 5 is a photoconductor drum as an image carrier, and 6 is a surface of the photoconductor drum 5. Charging device (charging charger), 7 is a transfer device (transfer roller) that transfers the toner image formed on the photoconductor drum 5 to the sheet P, and 8 is a transfer device that removes untransferred toner remaining on the photoconductor drum 5. Indicates a cleaning device.
Further, 10 is a document transport section for transporting the set document D to the document reading section 2, 12 is a paper feed section (paper cassette) in which a sheet P such as paper is stored, and 20 is a toner image on the sheet P. An unfixed image) is heated and fixed to the sheet P, 21 is a fixing roller installed in the fixing device 20, and 22 is a pressure roller installed in the fixing device 20.
Further, 30 is a collecting device that collects ozone generated in the image forming apparatus 1 together with suspended toner, 45 is a timing roller (resist roller) that conveys the sheet P toward the transfer device 7 (transfer nip), and 49 is. A waste toner collection container for collecting untransferred toner collected by the cleaning device 8 as waste toner, and 50 is an operation display for inputting various contents related to the operation of the image forming apparatus 1 and displaying information. Shows the panel.

With reference to FIG. 1, an operation during normal image formation in an image forming apparatus will be described.
First, the document D is conveyed from the document table in the direction of the arrow in the drawing by the transfer roller of the document transfer unit 10, and passes over the document reading unit 2. At this time, the document reading unit 2 optically reads the image information of the document D passing above.
Then, the optical image information read by the document reading unit 2 is converted into an electric signal and then transmitted to the exposure unit 3 (writing device). Then, the exposure light L (laser light) based on the image information of the electric signal is emitted from the exposure unit 3 toward the photoconductor drum 5.

On the other hand, the photoconductor drum 5 as an image carrier is rotated in the clockwise direction in the drawing, and is subjected to a predetermined image forming process (charging step, exposure step, developing step) to obtain image information on the photoconductor drum 5. A corresponding image (toner image) is formed. After that, the image formed on the photoconductor drum 5 is transferred onto the sheet P conveyed by the timing roller 45 at the position facing the transfer device 7 (transfer nip).

Specifically, the photoconductor drum 5 is rotated clockwise in FIG. 1. Then, first, the surface of the photoconductor drum 5 is uniformly charged at the position facing the charging device 6 (the charging step). In this way, a charging potential is formed on the photoconductor drum 5. In this embodiment, a known corona discharge type charging charger is used as the charging device 6.
After that, the surface of the charged photoconductor drum 5 reaches the irradiation position of the exposure light L. Then, an electrostatic latent image based on the image information read by the document reading unit 2 is formed on the surface of the photoconductor drum 5 (exposure step).
After that, the surface of the photoconductor drum 5 on which the electrostatic latent image is formed reaches a position facing the developing device 4. Then, toner is supplied from the developing device 4 onto the photoconductor drum 5, and the latent image on the photoconductor drum 5 is developed (in the developing process). The developing apparatus 4 functions as a toner accommodating apparatus in which toner as powder is accommodated.
After that, the surface of the photoconductor drum 5 after the developing step reaches a position facing the transfer device 7 (transfer nip). Then, at the position of the transfer device 7, the toner image formed on the photoconductor drum 5 is transferred onto the sheet P (this is a transfer step). A transfer bias having a polarity different from that of the toner is applied to the transfer device 7 (transfer roller).
Then, the surface of the photoconductor drum 5 after the transfer step reaches a position facing the cleaning device 8. Then, the cleaning device 8 removes and recovers the untransferred toner remaining on the photoconductor drum 5 (cleaning step). The untransferred toner collected in the cleaning device 8 is collected in the waste toner collection container 49 via a waste toner transfer path (not shown).
After that, the surface of the photoconductor drum 5 passes through the static elimination unit, and a series of image forming processes in the photoconductor drum 5 is completed.

On the other hand, the sheet P conveyed to the position (transfer nip) of the transfer device 7 operates as follows.
First, the uppermost sheet P of the sheets P housed in the paper feed unit 12 is fed by the paper feed rollers toward the transport path in which a plurality of transport roller pairs are installed. After that, the seat P reaches the position of the timing roller 45. Then, the sheet P that has reached the position of the timing roller 45 is conveyed to the transfer device 7 (transfer nip) at the same timing in order to align with the image formed on the photoconductor drum 5.

Then, the sheet P after the transfer step reaches the fixing device 20 via the transport path after passing through the position of the transfer device 7. The sheet P (the sheet P on which the unfixed image is supported) that has reached the fixing device 20 is fed between the fixing roller 21 (a heater as a heat source is internally provided) and the pressurizing roller 22. The toner image (image) is fixed by the heat received from the fixing roller 21 and the pressure received from both members 21 and 22. The sheet P on which the toner image is fixed is discharged from between the fixing roller 21 and the pressure roller 22 (which is a fixing nip), and then discharged from the image forming apparatus main body 1.
In this way, a series of image forming processes is completed.

Next, in the present embodiment, the collection device 30 installed in the image forming device 1 will be described in detail.
With reference to FIGS. 1 to 3, the image forming apparatus 1 in the present embodiment includes the ozone generated by the high-pressure discharge by the charging apparatus 6 at the time of image formation (during the charging step) and the periphery of the photoconductor drum 5. A collecting device 30 is provided for collecting toner (including paper dust) as a powder floating in the above and not discharging it to the outside of the device.
Specifically, the collecting device 30 is provided with a duct 31 for exhausting air from the vicinity of the charging device 6 toward the outside of the image forming apparatus main body 1. The duct 31 is on the upstream side in the ventilation direction and is provided with a suction port A (formed so as to extend in the width direction with reference to FIG. 3) in the vicinity of the charging device 6, and is on the downstream side in the ventilation direction. Is provided with a discharge port B exposed to the outside of the device. A filter 36 (ozone filter) and a fan 41 are provided in the path from the suction port A to the discharge port B of the duct 31.
Further, as the filter 36 (ozone filter), a known one can be used. In this embodiment, an ozone filter catalyzed by manganese oxide is used as the filter 36. Further, the size of the mesh of the filter 36 is set to be equal to or smaller than the particle size of the toner or the like to be collected so as to collect foreign substances such as toner and paper dust and allow only air (gas) to pass therethrough. Has been done.
Further, on the downstream side of the filter 36 (the downstream side in the ventilation direction indicated by the white arrow in FIGS. 1 to 3), the fan 41 (exhaust fan) that generates the air flow in the direction of the white arrow in FIGS. ) Is installed.
With such a configuration, in the duct 31, ozone generated by the high-voltage discharge by the charging device 6 is decomposed (collected) by the filter 36, and air (gas) having a small amount of ozone is discharged to the outside of the device from the discharge port B. Will be. Further, in the duct 31, the powder-free air (gas) is collected while the toner (including paper dust) as powder floating around the photoconductor drum 5 is collected by the filter 36. It will be discharged to the outside of the device from the discharge port B.

Hereinafter, the detection system 35 installed in the collection device 30 in the present embodiment will be described in detail.
As shown in FIGS. 2 and 3, a detection system 35 for detecting the state of the filter 36 is installed in the collection device 30. As shown in FIG. 4 (and FIG. 2), the detection system 35 includes a filter 36, a counter electrode 37, a detection unit 62 as a detection means, and the like.
The filter 36 is non-conductive and, as described above, is configured to be able to collect toner as a powder. Further, the filter 36 in the present embodiment is configured to be able to ventilate air (a gas in a state where ozone is removed). The filter 36 is provided with a counter electrode 37 composed of two electrode plates 37a and 37b. Both the filter 36 and the counter electrode 37 are arranged so that a gap is not formed between the filter 36 and the inner wall surface of the duct 31.
In addition, on the downstream side of the ventilation direction (the direction from the suction port A toward the exhaust port B, the direction of the white arrow in FIG. 2 and the direction of the arrow in FIG. 4) with respect to the filter 36 and the counter electrode 37, A fan 41 (exhaust fan) for ventilation is installed.

Here, the detection unit 62 as the detection means detects the change in the electric field formed in the counter electrode 37.
Specifically, the detection unit 62 (detection means) applies a predetermined voltage to the two electrode plates 37a and 37b by the power supply 61, so that the magnitude of the electric field formed between the two electrode plates 37a and 37b is large. The amount of change (more specifically, the amount of change ΔC of the capacitance C) is detected. Then, based on the detection result, the filter 36 determines the state (degree of clogging) in which the filter 36 is contaminated with toner (including paper dust and the like).

The capacitance C between the two electrode plates 37a and 37b is proportional to the relative permittivity of the region (insulator) where the electric field is formed, while the relative permittivity of toner and paper dust is the relative permittivity of air. As shown in FIG. 6, as the amount of toner and paper dust collected by the filter 36 (toner stain amount) increases, the change amount ΔC of the capacitance also increases proportionally.
In the present embodiment, based on such a mechanism, the detection unit 62 detects the amount of change in the capacitance (magnitude of the electric field) of the counter electrode 37, and the control unit 60 detects the change amount of the filter 36 based on the detection result. The degree of dirt is determined.

When the detection system 35 in the present embodiment detects a state in which the amount of change in the magnitude of the electric field of the counter electrode 37 exceeds a predetermined value by the detection unit 62 (detection means), the state is set to the outside. I am trying to notify you.
Specifically, when the detection unit 62 (detection means) detects a state in which the change amount ΔC of the capacitance in the electric field of the counter electrode 37 exceeds a predetermined value M (see FIG. 6), the filter 36 is a toner (see FIG. 6). The operation display panel 50 (see FIG. 1) as a display unit indicates that the filter 36 is clogged with the powder) and that the filter 36 needs to be replaced or maintained. An example of such a display is, for example, "The filter replacement time is approaching, so replace the filter according to the following procedure."
By performing such notification, it is possible to suppress a problem that the filter 36 is used in a clogged state.

Here, with reference to FIGS. 4 and 5, in the present embodiment, the counter electrode 37 is arranged so as to sandwich the filter 36 between the upstream side and the downstream side in the ventilation direction indicated by the arrow in FIG. Two mesh-structured electrode plates (upstream side electrode plate 37a and downstream side electrode plate 37b).
Further, the counter electrode 37 is formed so that the facing distance from the surface of the facing filter 36 is substantially uniform over the entire surface according to the shape of the surface of the facing filter 36.
Specifically, the upstream electrode plate 37a is a network structure made of a conductive material, and is in surface contact with the substantially rectangular parallelepiped filter 36 on the upstream side in the ventilation direction. The downstream electrode plate 37b is a network structure made of a conductive material, and is in surface contact with the substantially rectangular parallelepiped filter 36 on the downstream side in the ventilation direction.
By forming the two electrode plates 37a and 37b in a mesh structure, respectively, even if the electrode plates 37a and 37b are arranged so as to block the ventilation passage in the duct 31, the ventilation is hindered by the electrode plates 37a and 37b. It will not be done.

In particular, in the present embodiment, of the two electrode plates 37a and 37b, the upstream electrode plate 37a arranged on the upstream side in the ventilation direction is formed so that toner (powder) can pass through at least in addition to air. The downstream electrode plate 37b arranged on the downstream side in the ventilation direction is formed so as to allow at least air to pass through.
Specifically, as shown in FIG. 5, the mesh structure opening S1 (mesh size) in the upstream electrode plate 37a is formed to be larger than the mesh structure opening S2 in the downstream electrode plate 37b. (S1> S2). The opening S1 of the upstream electrode plate 37a is about several μm to several tens of μm, and is formed sufficiently larger than the particle size of the toner or paper dust.
With this configuration, air containing toner and paper dust (including ozone) passes through the upstream electrode plate 37a and reaches the filter 36, and the air from which ozone and powder have been removed is released. It is sent out from the filter 36 and smoothly passes through the downstream electrode plate 37b.
Here, in order to improve the detection accuracy of the electric field (capacitance) by the counter electrode 37, it is preferable that the openings S1 and S2 of the electrode plates 37a and 37b have the minimum necessary size. This is because when the sizes of the openings S1 and S2 become large, the surface area of the electrode plate becomes small, and the sensitivity for detecting the electric field (capacitance) decreases.
In the present embodiment, the shape of the mesh of the counter electrode 37 having a mesh structure is square, but the shape of the mesh is not limited to this, and for example, the shape of the mesh is hexagonal (honeycomb shape). You can also do it.

Further, with reference to FIG. 4, in the present embodiment, a filter 36 having a thickness Z (length in the ventilation direction) smaller than the vertical and horizontal dimensions X and Y is used. (Z <X, Y).
If the thickness Z of the filter 36 becomes large, the facing distance between the two electrode plates 37a and 37b becomes long, and the sensitivity for detecting the electric field (capacitance) decreases. Therefore, it is preferable to use an optimized filter 36 whose thickness Z is not too large.

As described above, in the present embodiment, since the change in the electric field formed in the counter electrode 37 installed in the filter 36 is detected, an obstacle (for example, a wall or the like) installed around the image forming apparatus 1 is detected. It is possible to accurately detect the state in which the filter 36 is clogged with the toner (powder) regardless of the above. That is, the problem that the state of the filter 36 cannot be detected accurately and is erroneously detected is reduced.

<Modification 1>
As shown in FIG. 7, the filter 36 in the modified example 1 is of a pleated structure (a structure in which mountains and valleys are alternately repeated).
The counter electrode 37 in the first modification is also formed so that the facing distance from the surface of the facing filter 36 is substantially uniform over the entire surface according to the shape of the surface of the facing filter 36. That is, in the first modification, the two electrode plates 37a and 37b are formed so that the peaks and valleys are alternately repeated according to the shape of the facing surface of the filter 3 having a pleated structure, respectively. The two electrode plates 37a and 37b are formed so that the facing distances are substantially uniform over the entire surface.
Even when the filter 36 and the counter electrode 37 are configured in this way, the state of the filter 36 can be detected with high accuracy.

<Modification 2>
As shown in FIG. 8, the detection system 35 in the second modification is installed in the developing device 4 as a toner accommodating device accommodating toner as powder.
The developing apparatus 4 as a toner accommodating apparatus has toner accommodating inside, and the toner is carried on a developing roller while stirring and transporting the toner in the apparatus, so that the photoconductor drum 5 is accommodated. It develops the latent image formed above.
Here, an opening is provided in the ceiling of the developing device 4 in order to prevent an increase in the internal pressure of the device, and a filter 36 is installed so as to close the opening. The filter 36 is a toner filter formed so as to collect toner and allow only air to pass through, and is made of a non-conductive non-woven fabric or the like. Then, the air in the developing device 4 (excess air for preventing the increase in internal pressure) is discharged from the discharge port B through the duct 31 through the filter 36 by suction by the fan 41. Become.
Here, also in the second modification, the counter electrode 37 is installed in the filter 36, and the change in the electric field formed in the counter electrode 37 is detected by the detection unit 62. Then, based on the detection result, the state of the filter 36 can be accurately grasped.
In the second modification, the detection system 35 is installed in the developing device 4 as the toner accommodating device, but the detection system 35 can also be installed in the waste toner recovery container 49 (see FIG. 1) as the toner accommodating device.

<Modification 3>
As shown in FIG. 9, in the detection system 35 (collecting device 30) in the modified example 3, a fan 42 (intake fan) for ventilating the filter 36 and the counter electrode 37 is provided upstream in the ventilating direction. is set up.
Specifically, air is sucked into the duct 31 from the intake port C of the image forming apparatus 1 by the fan 42, and floats around the ozone generated by the charging device 6 and the photoconductor drum 5 together with the sucked air. Toner and paper dust flow in the direction of the white arrow. Then, ozone, toner, and paper dust are collected by the filter 36, and clean air is discharged from the discharge port B.
Even in such a configuration, the state of the filter 36 can be accurately detected by the detection system 35.
The fan for ventilation may be arranged on at least one of the downstream side and the upstream side in the ventilation direction with respect to the filter 36 and the counter electrode 37, and the fan 41 in FIG. 2 and the fan 42 in FIG. 9 You may install both.

As described above, the detection system 35 in the present embodiment has a filter 36 capable of collecting toner (powder), a counter electrode 37 installed in the filter 36, and an electric field formed in the counter electrode 37. A detection unit 62 (detection means) for detecting a change is provided.
As a result, the state of the filter 36 can be detected with high accuracy.

In the present embodiment, the present invention is applied to the detection system 35 installed in the monochrome image forming apparatus 1, but the present invention is naturally applied to the detection system installed in the color image forming apparatus. Can be applied.
Further, in the present embodiment, the filter 36 for collecting powder together with ozone is used, and in the modification 2, the filter 36 for collecting toner is used, but if the filter is for collecting powder, Without being limited to these, for example, a VOC filter that collects volatile organic compounds generated by the fixing step by the fixing device 20 can be used.
Further, in the present embodiment, a substantially rectangular parallelepiped filter 36 is used, and in the first modification, a filter 36 having a pleated structure is used, but the filter is not limited to these as long as it collects powder. For example, a cylindrical filter can also be used. In that case, the counter electrode is formed so as to sandwich the outer peripheral surface and the inner peripheral surface of the cylindrical filter.
And even in those cases, the same effect as that of the present embodiment can be obtained.

It is clear that the present invention is not limited to the present embodiment, and the present embodiment may be appropriately modified in addition to the suggestions in the present embodiment within the scope of the technical idea of the present invention. be. Further, the number, position, shape and the like of the constituent members are not limited to the present embodiment, and the number, position, shape and the like suitable for carrying out the present invention can be used.

1 Image forming apparatus (image forming apparatus main body),
4 Developing device (toner accommodating device),
5 Photoreceptor drum (image carrier),
6 Charging device,
30 Collection device,
31 duct,
35 Detection system,
36 filters,
37 Opposite electrode,
37a upstream electrode plate, 37b downstream electrode plate,
41 fan (exhaust fan),
42 fan (intake fan),
50 Operation display panel (display unit),
62 Detection unit (detection means),
A suction port, B discharge port, C intake port.

Japanese Unexamined Patent Publication No. 2004-219875

Claims (10)

A filter that can collect powder and
With the counter electrode installed on the filter,
A detection means for detecting a change in the electric field formed on the counter electrode and
A detection system characterized by being equipped with. The detection system according to claim 1, wherein when the detection means detects a state in which the amount of change in the magnitude of the electric field exceeds a predetermined value, the state is notified to the outside. When the detection means detects a state in which the amount of change in capacitance in the electric field exceeds a predetermined value, the display unit displays that the filter is clogged with the powder. The detection system according to claim 1 or 2. When the detection means detects a state in which the amount of change in capacitance in the electric field exceeds a predetermined value, the display unit displays that the filter needs to be replaced or maintained. The detection system according to any one of claims 1 to 3. The invention according to any one of claims 1 to 4, wherein the counter electrode is an electrode plate having two mesh structures arranged so as to sandwich the filter between the upstream side and the downstream side in the ventilation direction. Detection system. Of the two electrode plates, the upstream electrode plate arranged on the upstream side in the ventilation direction is formed so as to allow the powder to pass through at least in addition to air, and the downstream side arranged on the downstream side in the ventilation direction. The detection system according to claim 5, wherein the side electrode plate is formed so as to allow at least air to pass through. One of claims 1 to 6, wherein the counter electrode is formed so that the facing distance from the surface of the filter is substantially uniform over the entire surface according to the shape of the surface of the filter facing the filter. The detection system described in. The invention according to any one of claims 1 to 7, wherein a fan for ventilating is installed on at least one of the downstream side and the upstream side in the ventilation direction with respect to the filter and the counter electrode. Detection system. A toner accommodating device in which toner as powder is accommodating.
A toner accommodating device comprising the detection system according to any one of claims 1 to 8. An image forming apparatus comprising the detection system according to any one of claims 1 to 8 or the toner accommodating device according to claim 9.

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