JP6911480B2 - Filter unit and image forming device - Google Patents

Description

The present invention relates to a filter unit and an image forming apparatus for removing foreign substances contained in a gas flowing through a blowing path.

Documents in which conventional filter units are disclosed include, for example, Japanese Patent Application Laid-Open No. 2006-232141 (Patent Document 1) and Japanese Patent Application Laid-Open No. 2014-1216887.

In the filter unit described in Patent Document 1, a reinforcing member is provided on the filter medium in order to prevent the filter medium from being deformed due to the pressure difference between the upstream side and the downstream side of the filter medium. By providing such a reinforcing member, the life of the filter unit can be extended.

The filter unit described in Patent Document 2 includes a filter medium formed by pleating to a predetermined size along the width direction, and a holding frame made of a soft material and provided along the outer edge of the filter medium. A reinforcing portion extending along a direction intersecting the width direction of the filter medium is provided so that one end side is connected to one end portion of the holding frame in the width direction and the other end is an open end. By providing such a reinforcing portion, delamination at the end of the filter medium and separation between the non-woven fabric and the holding frame are prevented even when an external force is intentionally applied to the holding frame without significantly increasing the ventilation resistance. can do.

Japanese Unexamined Patent Publication No. 2006-232141 Japanese Unexamined Patent Publication No. 2014-121687

When a gas is blown with a large air volume, the wind speed at the central portion tends to be high and the wind speed at the end side tends to be slow. In the filter unit described in Patent Document 1, overall deformation of the filter medium is prevented. Therefore, when the gas is blown with a large amount of air, the wind speed at the center of the airflow is high, the wind speed at the end of the airflow is kept low, and the gas passes through the filter unit. That is, the wind speed passing through the center of the filter unit is high, and the wind speed passing through the end side of the filter unit is slow.

In such a case, dust contained in the airflow can be collected on the end side of the filter unit where the wind speed becomes slow, but dust contained in the airflow can be collected on the central side of the filter unit where the wind speed increases. Increases the rate of passing through the filter unit.

In the filter unit described in Patent Document 2, the area where the reinforcing portion is provided is very small so as not to increase the ventilation resistance. Therefore, when gas is blown with a large amount of air, in most of the filter media, the filter media in adjacent portions come into contact with each other on the crease side (mountain side) of the filter medium located on the upstream side in the blowing direction, and the blowing direction. On the crease side (valley side) of the filter medium located on the downstream side of the above, the filter media in the adjacent portions are deformed so as to be separated from each other.

Therefore, when the gas is blown with a large amount of air, the wind speed at the center of the airflow is high, the wind speed at the end of the airflow is kept low, and the gas passes through the filter unit. In addition, as described above, some of the filter media are deformed so as to come into contact with each other, and the airflow passage area is reduced, so that the flow rate at the non-contact portion is increased. As a result, the wind speed passing through the non-contact portion becomes high, and as a result, the ratio of dust contained in the air flow passing through the filter unit increases.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a filter unit capable of improving the collection efficiency of foreign substances containing gas and an image forming apparatus provided with the filter unit. To provide.

The filter unit based on the present invention is a filter unit installed in the exhaust path and collecting foreign matter contained in the gas flowing through the exhaust path, and is provided so that the peaks and valleys are alternately continuous. A filter unit including at least one or more pleated filter media is provided. The filter medium includes a first surface located on the upstream side and a second surface located on the downstream side in the gas blowing direction, and is arranged so that the mountain portion is located on the upstream side. The filter unit includes a first collection area and a second collection area surrounding the first collection area. When the gas passes through the filter portion and is deformed so that the second surfaces facing each other across the mountain portion in the first collection region are in contact with each other on the mountain portion side, the first collection region Ventilation resistance is applied to both sides of the first collection region in the first direction parallel to the ridgeline direction of the mountain portion and both sides of the first collection region in the second direction orthogonal to the first direction. The filter unit is configured so as to be larger than the ventilation resistance of the second collection region located.

In the filter unit based on the present invention, the filter unit may include a plurality of the filter media arranged in a matrix. In this case, the plurality of filter media may include a plurality of outer edge defining filter media that define the outer edge of the first collection region. Further, in this case, each of the plurality of outer edge defined filter media preferably has a low resistance portion having a small ventilation resistance at an end portion near the center of the filter portion, and is located on the end portion side far from the center of the filter portion. It is preferable to have a high resistance portion having a large ventilation resistance. Further, it is preferable that the outer edge of the first collection region is defined by the continuous low resistance portions of the plurality of outer edge defining filter media.

In the filter unit based on the present invention, the filter unit may include a plurality of the filter media arranged in a matrix. In this case, the first collection region may be composed of one or more of the filter media arranged in the central portion of the filter portion. Further, in this case, it is preferable that the second collection region is composed of a plurality of other filter media arranged so as to surround the one or more filter media.

In the filter unit based on the present invention, the second collection region may be provided with a plurality of reinforcing members extending in a direction intersecting the first direction to reinforce the filter medium. ..

In the filter unit based on the present invention, it is preferable that the plurality of reinforcing members extend along the second direction. In this case, the reinforcing members located on both ends of the first collecting region in the first direction are longer than the reinforcing members located on both ends of the first collecting region in the second direction. Is preferable.

In the filter unit based on the present invention, it is preferable that each of the plurality of reinforcing members has a comb tooth shape that fits into the filter medium.

In the filter unit based on the present invention, the distance between the adjacent peaks in the first collection region is different from the distance between the adjacent peaks in the second collection region. May be good.

In the filter unit based on the present invention, the filter medium of the portion constituting the first collection region and the filter media of the portion constituting the second collection region may be separate members. In this case, it is preferable that the strength of the filter medium in the portion constituting the first collection region is lower than the strength of the filter medium in the portion constituting the second collection region.

In the filter unit based on the present invention, it is preferable that the thickness of the filter medium in the first collection region is thinner than the thickness of the filter medium in the second collection region.

In the filter unit based on the present invention, the first collection region preferably has a rectangular shape, a circular shape, or an oval shape when viewed from the gas blowing direction.

The image forming apparatus based on the present invention includes the filter unit and a housing for accommodating the image forming portion inside, and the air in the housing is passed through the filter unit and discharged to the outside of the housing.

The image forming apparatus based on the present invention further includes a fixing portion arranged in the housing and an exhaust path for discharging air containing ultrafine particles generated in the fixing portion to the outside of the housing. Is preferable. In this case, it is preferable that the filter unit is arranged in the exhaust path.

The image forming apparatus based on the present invention changes the output of the blower and the blower that blows air containing ultrafine particles generated in the fixing portion so as to be discharged to the outside of the housing through the exhaust path. It may further include a control unit.

In the image forming apparatus based on the present invention, it is preferable that the control unit increases the output of the blower when the image coverage is large as compared with the case where the image coverage is small.

The image forming apparatus based on the present invention may further include a temperature detecting unit for detecting the temperature of the fixing unit. In this case, when the control unit determines that the fixing temperature is high based on the detection result of the temperature detection unit, the output of the blower is increased as compared with the case where the fixing temperature is determined to be low. Is preferable.

According to the present invention, it is possible to provide a filter unit capable of improving the collection efficiency of foreign substances contained in a gas and an image forming apparatus provided with the filter unit.

It is the schematic which shows the image forming apparatus which concerns on Embodiment 1. FIG. It is a perspective view which shows the fixing part and the exhaust path which concerns on Embodiment 1. FIG. It is a perspective view which shows the filter unit which concerns on Embodiment 1. FIG. It is a front view which shows the filter unit which concerns on Embodiment 1. FIG. It is sectional drawing which shows the filter unit which concerns on Embodiment 1. FIG. It is a figure which shows the state that the air flow with a slow wind speed passes through the filter unit in the 1st comparative example. It is a figure which shows the state that the air flow with a high wind speed passes through the filter unit in the 1st comparative example. FIG. 7 is an enlarged view showing the state of the filter medium of the filter unit in the first comparative example. It is a figure which shows the state that the air flow with a high wind speed passes through the filter unit in the 2nd comparative example. It is a figure which shows the state that the air flow with a high wind speed passes through the filter unit which concerns on Embodiment 1. FIG. It is a front view which shows the filter unit which concerns on Embodiment 2. FIG. It is sectional drawing which shows the filter unit which concerns on Embodiment 2. FIG. It is a front view which shows the filter unit which concerns on Embodiment 3. It is a front view which shows the filter unit which concerns on Embodiment 4. FIG. It is a front view which shows the filter unit which concerns on Embodiment 5. It is a front view which shows the filter unit which concerns on Embodiment 6. It is a figure which shows the image forming apparatus which concerns on Embodiment 7. It is sectional drawing which shows the fixing part and the exhaust path which concerns on Embodiment 7. It is a figure which shows the condition and result of the verification experiment performed in order to verify the effect which concerns on embodiment.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the embodiments shown below, the same or common parts are designated by the same reference numerals in the drawings, and the description thereof will not be repeated.

(Embodiment 1)
FIG. 1 is a schematic view showing an image forming apparatus according to the first embodiment. The image forming apparatus 100 according to the first embodiment will be described with reference to FIG.

FIG. 1 shows an image forming apparatus 100 as a color printer. Hereinafter, the image forming apparatus 100 as a color printer will be described, but the image forming apparatus 100 is not limited to the color printer. For example, the image forming apparatus 100 may be a monochrome printer, a fax machine, or a monochrome printer, a color printer, and a multi-function peripheral (MFP).

The image forming apparatus 100 includes image forming units 1Y, 1M, 1C, 1K, an intermediate transfer belt 30, a primary transfer roller 31, a secondary transfer roller 33, a cassette 37, a driven roller 38, and a drive roller 39. A timing roller 40, a fixing portion 50, a housing 90, and a control device 101 are provided.

The housing 90 defines the outer shell of the image forming apparatus 100B. The housing 90 contains an image forming unit 1Y, 1M, 1C, 1K, an intermediate transfer belt 30, a primary transfer roller 31, a secondary transfer roller 33, a cassette 37, a driven roller 38, and a drive roller. 39, a timing roller 40, a fixing portion 50, an exhaust duct 60 as an exhaust path, and a control device 101 are housed.

By the image forming unit 1Y, 1M, 1C, 1K, the intermediate transfer belt 30, the primary transfer roller 31, the secondary transfer roller 33, the cassette 37, the driven roller 38, the drive roller 39, and the timing roller 40. An image forming unit is configured. This image forming unit forms a toner image on the recording medium S as a recording medium conveyed along the transfer path 41 described later.

The image forming units 1Y, 1M, 1C, and 1K are arranged in order along the intermediate transfer belt 30. The image forming unit 1Y receives the toner supply from the toner bottle 15Y and forms a yellow (Y) toner image. The image forming unit 1M receives the toner supply from the toner bottle 15M and forms a toner image of magenta (M). The image forming unit 1C receives the toner supply from the toner bottle 15C and forms a toner image of cyan (C). The image forming unit 1K receives the toner supply from the toner bottle 15K and forms a black (BK) toner image.

The image forming units 1Y, 1M, 1C, and 1K are arranged along the intermediate transfer belt 30 in the order of rotation of the intermediate transfer belt 30, respectively. The image forming units 1Y, 1M, 1C, and 1K each include a photoconductor 10, a charging device 11, an exposure device 12, a developing device 13, and a cleaning device 17, respectively.

The charging device 11 uniformly charges the surface of the photoconductor 10. The exposure device 12 irradiates the photoconductor 10 with a laser beam in response to a control signal from the control device 101, and exposes the surface of the photoconductor 10 according to the input image pattern. As a result, an electrostatic latent image corresponding to the input image is formed on the photoconductor 10.

The developing apparatus 13 applies a developing bias to the developing roller 14 while rotating the developing roller 14, and adheres toner to the surface of the developing roller 14. As a result, the toner is transferred from the developing roller 14 to the photoconductor 10, and the toner image corresponding to the electrostatic latent image is developed on the surface of the photoconductor 10.

The photoconductor 10 and the intermediate transfer belt 30 are in contact with each other at a portion where the primary transfer roller 31 is provided. The primary transfer roller 31 has a roller shape and is configured to be rotatable. By applying a transfer voltage having the opposite polarity to the toner image to the primary transfer roller 31, the toner image is transferred from the photoconductor 10 to the intermediate transfer belt 30. The yellow (Y) toner image, the magenta (M) toner image, the cyan (C) toner image, and the black (BK) toner image are superimposed in this order and transferred from the photoconductor 10 to the intermediate transfer belt 30. As a result, a color toner image is formed on the intermediate transfer belt 30.

The intermediate transfer belt 30 is stretched on the driven roller 38 and the driving roller 39. The drive roller 39 is rotationally driven by, for example, a motor (not shown). The intermediate transfer belt 30 and the driven roller 38 rotate in conjunction with the drive roller 39. As a result, the toner image on the intermediate transfer belt 30 is transferred to the secondary transfer roller 33.

The cleaning device 17 is pressure-contacted with the photoconductor 10. The cleaning device 17 collects the toner remaining on the surface of the photoconductor 10 after the transfer of the toner image.

The recording medium S is set in the cassette 37. The recording medium S is sent from the cassette 37 one by one to the secondary transfer roller 33 along the transport path 41 by the timing roller 40. The secondary transfer roller 33 has a roller shape and is configured to be rotatable. The secondary transfer roller 33 applies a transfer voltage having a polarity opposite to that of the toner image to the recording medium S being conveyed. As a result, the toner image is attracted from the intermediate transfer belt 30 to the secondary transfer roller 33, and the toner image on the intermediate transfer belt 30 is transferred. The transfer timing of the recording medium S to the secondary transfer roller 33 is adjusted by the timing roller 40 according to the position of the toner image on the intermediate transfer belt 30. The timing roller 40 transfers the toner image on the intermediate transfer belt 30 to an appropriate position on the recording medium S.

The fixing portion 50 includes a cover member 51 and a fixing device 52. The cover member 51 defines an internal space and is configured to allow the recording medium S to pass through. The fixing device 52 includes fixing rollers such as a pressure roller 53 and a heating roller 54. The fixing device 52 is driven by a fixing device driving unit (not shown).

The fixing device 52 pressurizes and heats the recording medium S passing through itself. As a result, the toner image is fixed on the recording medium S. The fixing device 52 fixes the toner image on the recording medium S that is conveyed along the conveying path 41. The recording medium S on which the toner image is fixed is discharged to the tray 48.

An exhaust duct 60 (exhaust path) for purifying a gas containing foreign matter such as ultrafine particles generated in the fixing portion 50 and discharging it to the outside of the housing 90 is provided on the downstream side of the fixing portion 50 in the transport direction. Has been done.

Although the image forming apparatus 100 that employs the tandem method as the printing method has been described above, the printing method of the image forming apparatus 100 is not limited to the tandem method. The arrangement of each configuration in the image forming apparatus 100 can be appropriately changed according to the printing method adopted. As the printing method of the image forming apparatus 100, a rotary method or a direct transfer method may be adopted. In the case of the rotary system, the image forming apparatus 100 is composed of one photoconductor 10 and a plurality of developing apparatus 13 rotatably configured on the same axis. At the time of printing, the image forming apparatus 100 guides each developing apparatus 13 to the photoconductor 10 in order to develop a toner image of each color. In the case of the direct transfer method, the image forming apparatus 100 directly transfers the toner image formed on the photoconductor 10 to the recording medium S.

FIG. 2 is a perspective view showing a fixing portion and an exhaust path according to the first embodiment. The structure of the fixing portion and the exhaust path thereof according to the first embodiment will be described with reference to FIG.

As shown in FIG. 2, the cover member 51 accommodating the fixing device 52 includes a first cover portion 51A covering the pressure roller 53 side and a second cover portion 51B covering the heating roller 54 side. Includes 51B. A gap for passing the recording medium S is provided between the first cover portion 51A and the second cover portion 51B.

A temperature detection unit 75 for detecting the fixing temperature of the fixing device 52 is provided in the cover member 51. The temperature detection unit 75 is arranged near the outer peripheral surface of the heating roller 54. The detection result by the temperature detection unit 75 is input to the control device 101. The control device 101 controls the output of the blower 70, which will be described later, based on the detection result.

The exhaust duct 60 has an upstream portion 60A and a downstream portion 60B. The upstream portion 60A is provided with suction ports 601A and 601B for sucking the air in the fixing portion 50. The downstream portion 60B is provided with an exhaust port 60c for discharging air toward the outside of the housing 90. The downstream portion 60B is configured to have a larger internal cross-sectional area than the upstream portion 60A.

A blower 70 and a plurality of filter units 80 are arranged in the exhaust duct 60. More specifically, a blower and a plurality of filter units 80 are arranged in the downstream portion 60B of the exhaust duct 60. The blower 70 is provided on the exhaust port 60c side, and the plurality of filter units 80 are arranged on the upstream side of the blower 70. The details of the filter unit 80 will be described later with reference to FIGS. 3 to 5.

The blower 70 blows air containing ultrafine particles generated in the fixing portion 50 so as to be discharged to the housing 90 side through the exhaust duct 60. The ultrafine particles contained in the air are collected by the filter unit 80, and the purified air is discharged from the exhaust port 60c of the exhaust duct 60 by passing through the filter unit 80.

The output of the blower 70 is changed by the control device 101. When the control device 101 determines that the fixing temperature is high based on the detection result of the temperature detection unit 75, the output of the blower is increased as compared with the case where the fixing temperature is determined to be low. When the fixing temperature is high, a large amount of ultrafine particles may be generated. In such a case, by increasing the output of the blower 70, a gas containing a high concentration of superpartners can be exhausted.

Further, when the temperature detection unit 75 is not used, the control device 101 increases the output of the blower when the image coverage is large as compared with the case where the image coverage is small. In such a case, by increasing the output of the blower 70, a gas containing a high concentration of superpartners can be exhausted.

FIG. 3 is a perspective view showing a filter unit according to the first embodiment. FIG. 4 is a front view showing the filter unit according to the first embodiment. FIG. 5 is a cross-sectional view showing a filter unit according to the first embodiment. The filter unit 80 according to the first embodiment will be described with reference to FIGS. 3 to 5.

As shown in FIGS. 3 to 5, the filter unit 80 includes a filter unit 800 and a frame body 84. The frame body 84 is formed according to the shape of the air passage (exhaust path). The frame body 84 is made of, for example, a resin member.

The filter portion 800 includes a pleated filter medium 81 provided so that peak portions P1 and valley portions P2 are alternately continuous. The filter medium 81 is arranged so that the mountain portion P1 is located on the upstream side in the blowing direction.

The filter medium 81 includes a first surface 81a located on the upstream side and a second surface 81b located on the downstream side in the gas blowing direction. The first surface 81a side is composed of the dense layer 83, and the second surface 81b side is composed of the rough layer 82. The filter medium 81 is composed of a laminated non-woven fabric in which a coarse layer 82 and a dense layer 83 are joined and laminated. Since the filter medium 81 is formed in a pleated shape, a large filtration area can be secured.

The filter unit 800 includes a first collection area R1 located in the central portion and a second collection area R2 surrounding the first collection area R1. The first collection region R1 has a substantially rectangular shape when viewed along the gas blowing direction. The second collection region R2 has a frame-like shape when viewed along the gas blowing direction.

A plurality of reinforcing members 85 for reinforcing the filter medium 81 are provided in the second collecting region R2. The plurality of reinforcing members 85 extend in a direction intersecting the first direction DR1 parallel to the ridgeline direction of the mountain portion P1. The plurality of reinforcing members 85 extend, for example, in the second direction DR2 orthogonal to the first direction DR1.

The plurality of reinforcing members 85 are provided so as to extend linearly. The plurality of reinforcing members 85 are provided so as to enter the gap between the mountain portions P1 and the gap between the valley portions P2. In this case, it is preferable that the plurality of reinforcing members 85 are joined to the first surface 81a and the second surface 81b of the filter medium 81 by adhesion or the like.

For example, the reinforcing member 85 is made of a resin material in a cured state. Further, it may be composed of an adhesive or the like. The reinforcing member 85 is configured so that when an air flow having a high wind speed passes through the filter portion 800, deformation in which the second surfaces 81b facing each other across the mountain portion P1 come into contact with each other on the mountain portion P1 side is suppressed. It suffices if it is done.

The plurality of reinforcing members 85 are provided on both sides of the first collection region R1 in the first direction DR and on both sides of the first collection region R1 in the second direction DR2.

As a result, as will be described later, when the gas passes through the filter portion, the second surfaces 81b facing each other across the mountain portion P1 in the first collection region R1 are deformed so as to come into contact with each other on the mountain portion P1 side. , The ventilation resistance of the first collection region R1 is applied to both sides of the first collection region R1 in the first direction DR1 and both sides of the first collection region R1 in the second direction DR2 orthogonal to the first direction DR1. The filter unit 800 is configured so as to be larger than the ventilation resistance of the second collection region R2 located.

Of the plurality of reinforcing members 85, the reinforcing members 85 located on both ends of the first collecting region R1 in the first direction DR1 are more than the reinforcing members 85 located on both sides of the first collecting region R1 in the second direction DR2. long.

The reinforcing members 85 located on both end sides of the first collection region R1 in the second direction DR2 are connected to the frame body 84 on the root side and open ends on the tip side.

Here, a state in which the air flow passes through the filter unit 80 will be described with reference to a comparative example. FIG. 6 is a diagram showing a state in which an air flow having a slow wind speed passes through the filter unit in the first comparative example. FIG. 7 is a diagram showing a state in which an air flow having a high wind speed passes through the filter unit in the first comparative example. FIG. 8 is an enlarged view showing the state of the filter medium of the filter unit in the first comparative example in FIG. 7.

The filter unit 80X1 in the first comparative example is different from the filter unit 80 according to the first embodiment in that no reinforcing member is provided, and the other configurations are substantially the same.

As shown in FIG. 6, when the wind speed is slow, the difference in wind speed between the center side of the airflow F and the end side of the airflow F is small. Further, since the wind pressure is small, the filter medium 81 is not deformed. As a result, the airflow F passes through without reducing the filtration area, so that the foreign matter 95 such as ultrafine particles contained in the airflow F can be sufficiently collected by the filter unit.

On the other hand, as shown in FIG. 7, when the wind speed is high, the difference in wind speed between the center side of the airflow F and the end side of the airflow F is large. Further, since the wind pressure becomes large, the filter medium 81 is deformed. At this time, since the filter unit 80X1 is not provided with the reinforcing member, the filter medium 81 is deformed as a whole.

Specifically, as shown in FIG. 8, the second surfaces 81b facing each other across the mountain portion P1 are deformed so as to come into contact with each other on the mountain portion P1 side, and the first surfaces 81a facing each other across the valley portion P2 are deformed. Deforms to separate. As a result, the contact portion S1 is formed on the mountain portion P1 side, and the non-contact portion S2 is formed on the valley portion P2 side.

Since the contact portion S1 is formed uniformly in the filter portion 800, the ventilation resistance of the filter medium 81 increases as a whole due to the deformation of the filter medium 81. Therefore, when the airflow F passes through the filter unit 800 (filter medium 81), the wind speed at the center of the airflow F is high and the wind speed at the end side of the airflow F is low.

On the other hand, in the contact portion S1, the airflow F cannot pass, and the portion through which the airflow F can pass through the filter portion 800 is only the non-contact portion S2, and the airflow passage area of the filter portion 800 is reduced. Therefore, in the filter unit 80X1 in the first comparative example, the wind speed passing through the non-contact portion S2 becomes high, and as a result, the ratio of foreign matter 95 such as ultrafine particles contained in the airflow F passing through the filter portion 800 increases. ..

FIG. 9 is a diagram showing a state in which an air flow having a high wind speed passes through the filter unit in the second comparative example.

The filter unit 80X2 in the second comparative example is different from the filter unit 80 according to the first embodiment in that the reinforcing members are uniformly provided as a whole. Other configurations are almost the same.

As shown in FIG. 9, in the filter unit 80X2 in the second comparative example, the reinforcing members are uniformly provided as a whole. Therefore, even when the airflow F having a high wind speed passes through the filter unit 80X2, the deformation of the filter medium 81 is prevented. Therefore, the wind speed at the center of the airflow F is high, and the wind speed is maintained at the end side of the airflow F, so that the airflow F passes through the filter unit 80X2. That is, the wind speed passing through the central portion of the filter unit 80X2 is high, and the wind speed passing through the end portion side of the filter unit 80X2 is slow.

As a result, in the filter unit 80X2 in the second comparative example, the foreign matter 95 contained in the airflow F can be collected on the end side of the filter unit 80X2 where the wind speed becomes slow, but the filter unit 80X2 which increases the wind speed On the central side, the ratio of foreign matter 95 contained in the airflow F passing through the filter unit 80X2 is high.

FIG. 10 is a diagram showing a state in which an air flow having a high wind speed passes through the filter unit according to the first embodiment.

Here, in the filter unit 80 according to the first embodiment, as described above, the reinforcing member 85 is not provided in the first collecting region R1, and the reinforcing member 85 is provided only in the second collecting region R2. Is provided.

Therefore, as shown in FIG. 10, when the airflow F having a high wind speed passes through the filter unit 80, the deformation of the filter medium 81 is suppressed on the second collection region R2 side, and the deformation of the filter medium 81 is suppressed in the first collection region R1. The filter medium 81 is deformed.

Specifically, in the first collection region R1, the second surfaces 81b facing each other across the mountain portion P1 are deformed so as to come into contact with each other on the mountain portion P1 side, and the first surface 81a facing each other across the valley portion P2. Deforms so that

In the first collection region R1, the second surfaces 81b facing each other come into contact with each other on the mountain portion P1 side to form the contact portion S1, so that the contact portion S1 becomes a resistance when the air flow F passes through. On the other hand, in the second collection region R2, the reinforcing member 85 suppresses the deformation of the filter medium 81. As a result, as the filter medium 81 is deformed in the first collection region R1 as described above, the aeration resistance of the first collection region R1 is increased on both sides of the first collection region R1 in the first direction DR1 and on the first side. It is larger than the ventilation resistance of the second collection region R2 located on each side of the first collection region R1 in the two-way DR2.

By increasing the ventilation resistance of the first collection region R1, the wind speed in the central portion of the airflow F is reduced, and the speed of the airflow F is substantially averaged in the flow path. As a result, the foreign matter 95 contained in the airflow F can be sufficiently collected in the first collection area R1.

As described above, in the filter unit 80 according to the first embodiment, the collection efficiency of the foreign matter 95 contained in the gas can be improved, and in the image forming apparatus 100 using the foreign matter 95, the foreign matter is collected. It is possible to prevent 95 from being discharged to the outside.

(Embodiment 2)
FIG. 11 is a front view showing the filter unit according to the second embodiment. FIG. 12 is a cross-sectional view showing a filter unit according to the second embodiment. The filter unit 80A according to the second embodiment will be described with reference to FIGS. 11 and 12.

As shown in FIGS. 11 and 12, the filter unit 80A according to the second embodiment has a different configuration of the plurality of reinforcing members 85A when compared with the filter unit 80 according to the first embodiment. Other configurations are almost the same.

Each of the plurality of reinforcing members 85A has a comb tooth shape that fits into the filter medium 81. Each of the plurality of reinforcing members 85A is provided so as to fit into the filter medium 81 from the second surface 81b side. The plurality of reinforcing members 85A may be provided so as to fit into the filter medium 81 from the first surface 81a side.

Even in the case of the above configuration, the filter unit 80A according to the second embodiment has almost the same effect as the filter unit 80 according to the first embodiment.

(Embodiment 3)
FIG. 13 is a front view showing the filter unit according to the third embodiment. The filter unit 80B according to the third embodiment will be described with reference to FIG.

As shown in FIG. 13, the filter unit 80B according to the third embodiment has a different shape of the first collection region R1 when compared with the filter unit 80 according to the first embodiment. For other configurations, is almost the same.

The first collection region R1 is provided so as to have an elliptical shape when viewed along the blowing direction of the gas. The first collection region R1 is not limited to an elliptical shape, and may have an oval shape including an oval shape, a track shape, and the like.

In this case, the lengths of the plurality of reinforcing members 85 along the second direction DR2 become longer from the center line C1 of the filter portion 800 parallel to the second direction DR2 toward the outside along the first direction DR1. It is provided so as to include a part.

Even in the case of the above configuration, in the filter unit 80B according to the third embodiment, substantially the same effect as that of the first embodiment can be obtained.

(Embodiment 4)
FIG. 14 is a front view showing the filter unit according to the fourth embodiment. The filter unit 80C according to the fourth embodiment will be described with reference to FIG.

As shown in FIG. 14, the filter unit 80C according to the fourth embodiment has a different shape of the first collection region R1 when compared with the filter unit 80 according to the first embodiment. Other configurations are almost the same.

The first collection region R1 has a rectangular shape with the second direction DR2 as the longitudinal direction when viewed along the gas blowing direction. The first collection region R1 may have a rectangular shape with the first direction DR1 as the longitudinal direction.

Even in the case of the above configuration, in the filter unit 80C according to the fourth embodiment, substantially the same effect as that of the first embodiment can be obtained.

(Embodiment 5)
FIG. 15 is a front view showing the filter unit according to the fifth embodiment. The filter unit 80D according to the fifth embodiment will be described with reference to FIG.

As shown in FIG. 15, the filter unit 80D according to the fifth embodiment is mainly different in the configuration of the filter unit 800D when compared with the filter unit 80 according to the first embodiment. Other configurations are almost the same.

The filter unit 800D includes a plurality of filter media 81 arranged in a matrix. For example, the filter unit 800D is composed of four filter media 81 arranged in 2 rows and 2 columns. The frame 84D is formed in a grid pattern so as to surround each of the four filter media 81.

The plurality of filter media 81 includes a plurality of outer edge defining filter media that define the outer edge of the first collection region R1. In the present embodiment, the plurality of outer edge defined filter media correspond to four filter media 81. Further, when a plurality of filter media 81 are arranged in a matrix, the outer edge regulation filter medium refers only to the filter medium 81 that defines the outer edge of the first collection region R1.

Each of the plurality of outer edge defined filter media is provided at an end portion of the filter portion 800D near the center O1 and is assembled to form at least a part of the first collection region R1. And the divided second collection area R4 which is provided on the end side far from the center O1 of the filter unit 800D and which constitutes at least a part of the second collection area R2 by gathering. The outer edge of the first collection area R1 is defined by the continuous division of the first collection area R3 of the plurality of outer edge defining filter media.

In the present embodiment, the divided first collection region R3 is provided at a corner of each of the four filter media 81 near the center O1 of the filter unit 800D. The divided second collection region R4 is provided on the end side far from the center O1 of the filter unit 800D in each of the four. The divided first collection area R3 is not provided with the reinforcing member 85, and the divided second collection area R4 is provided with a plurality of reinforcing members 85.

Even in the case of the above configuration, in the filter unit 80D according to the fifth embodiment, substantially the same effect as that of the first embodiment can be obtained.

(Embodiment 6)
FIG. 16 is a front view showing the filter unit according to the sixth embodiment. The filter unit 80E according to the sixth embodiment will be described with reference to FIG.

As shown in FIG. 16, the filter unit 80E according to the sixth embodiment has a different configuration of the filter unit 800E when compared with the filter unit 80 according to the first embodiment, and the other configurations are substantially the same. Is.

The filter unit 800E includes a plurality of filter media 81 arranged in a matrix. The filter unit 800E is composed of, for example, nine filter media 81 arranged in 3 rows and 3 columns. The frame 84E is formed in a grid pattern so as to surround each of the four filter media 81.

In the present embodiment, the first collection region R1 is composed of a single filter medium 81 arranged in the central portion of the filter unit 800E, and the second collection region R2 is a single collection region R2 arranged in the central portion. It is composed of eight filter media 81 that surround the filter media 81.

When a plurality of filter media 81 are further arranged in a matrix, the first collection region R1 is formed by the plurality of filter media 81 arranged in the central portion, and the plurality of filter media arranged in the central portion. The second collection region R2 may be composed of a plurality of filter media 81 surrounding the periphery of the 81.

The filter medium 81 constituting the first collection region R1 is not provided with the reinforcing member 85, and each of the plurality of filter media 81 constituting the second collection region R2 is provided with a plurality of reinforcing members 85. ing.

Even in the case of the above configuration, in the filter unit 80E according to the sixth embodiment, substantially the same effect as that of the first embodiment can be obtained.

(Embodiment 7)
FIG. 17 is a diagram showing an image forming apparatus according to the seventh embodiment. The image forming apparatus 100F according to the ninth embodiment will be described with reference to FIG.

As shown in FIG. 17, the image forming apparatus 100F according to the ninth embodiment is mainly different from the image forming apparatus 100 according to the first embodiment in the installation position of the exhaust duct 60F. Other configurations are almost the same.

FIG. 18 is a cross-sectional view showing a fixing portion and an exhaust path according to the ninth embodiment. The fixing portion 50 and the exhaust duct 60 according to the ninth embodiment will be described with reference to FIG.

As shown in FIG. 18, the fixing portion 50 according to the ninth embodiment has substantially the same configuration as the fixing portion 50 according to the first embodiment. The exhaust duct 60F according to the ninth embodiment is provided on the upstream side of the fixing portion 50 in the transport direction of the recording medium as compared with the exhaust duct 60 according to the first embodiment.

A blower 70 and a filter unit 80 are arranged in the exhaust duct 60F. The filter unit 80 is provided on the exhaust port 60c side, and the blower 70 is arranged on the upstream side of the filter unit 80.

The image forming apparatus 100F may be configured in this way, and the arrangement of the exhaust duct 60F and the configuration of the blower 70 and the filter unit 80 in the exhaust duct 60F can be appropriately changed.

(Verification experiment)
FIG. 19 is a diagram showing conditions and results of a verification experiment for verifying the effect according to the embodiment. With reference to FIG. 19, the conditions and results of the verification experiment performed to verify the effect according to the embodiment will be described.

In the verification experiment, the filter units according to Comparative Examples and Examples were prepared, and the number of ultrafine particles passing through the filter unit was measured when a gas containing ultrafine particles was passed through these filter units. More specifically, the number of ultrafine particles that have passed through the central portion (first collection region R1) of the filter unit corresponding to the central portion of the airflow, and the end portion (second) of the filter unit corresponding to the end portion of the airflow. The number of ultrafine particles that passed through the collection area R2) was measured. As a measuring device, P-Track, which is an ultrafine particle counter, was used.

The area ratio between the first collection region R1 and the second collection region R2 is 1: 1, and the number of ultrafine particles that have passed through the central portion (first collection region R1) of the filter unit and the end of the air flow. The average value with the number of ultrafine particles that passed through the end portion (second collection area R2) of the filter unit corresponding to the above was calculated. The average value in the comparative example and the average value in the example were compared.

As the filter unit according to the comparative example, the filter unit 80X2 according to the second comparative example described above was prepared. That is, as the filter unit according to the comparative example, a reinforcing member is uniformly provided as a whole, and a filter medium 81 is prevented from being deformed even when the airflow F having a high wind speed passes through the filter unit 80X2. ..

As the filter unit according to the embodiment, the filter unit 80 according to the above-described first embodiment was prepared. That is, as the filter unit according to the embodiment, a filter unit in which the reinforcing member 85 is not provided in the first collecting region R1 and the reinforcing member 85 is provided only in the second collecting region R2 is prepared.

As the gas to pass through each filter unit, a gas containing 400,000 ultrafine particles on the upstream side of the filter unit was used. Each gas having a wind speed of 0.5 m / s and 0.8 m / s in the central portion was passed through the filter unit.

In the comparative example, when the wind speed at the central portion is 0.5 m / s, the wind speed at the central portion is maintained at 0.5 m / s when passing through the filter unit, and the wind speed at the end portion is It was 0.39 m / s. At this time, the number of ultrafine particles that passed through the central portion of the filter unit was 14549, and the number of ultrafine particles that passed through the end portion of the filter unit was 8185. On average, the number of ultrafine particles that passed through the filter unit was 11567.

In the comparative example, when the wind speed at the central portion is 0.8 m / s, the wind speed at the central portion is maintained at 0.8 m / s when passing through the filter unit, and the wind speed at the end portion is It was 0.58 m / s. At this time, the number of ultrafine particles that passed through the central portion of the filter unit was 30346, and the number of ultrafine particles that passed through the end of the filter unit was 14402. On average, the number of ultrafine particles that passed through the filter unit was 22374.

In the embodiment, when the wind speed at the central portion is 0.5 m / s, the central portion (first collection region R1) of the filter unit is deformed as described above, so that the wind speed passes through the filter unit. The wind speed at the center was 0.44 m / s, and the wind speed at the ends was 0.46 m / s. In this way, the wind speed of the airflow F passing through the filter unit was substantially averaged as a whole, and the wind speed of the airflow F passing through the filter unit was 0.45 m / s. At this time, the number of ultrafine particles that passed through the central portion (first collection region R1) of the filter unit was 10671, and the number of ultrafine particles that passed through the end portion (second collection region R2) of the filter unit. Was 11,356. On average, the number of ultrafine particles that passed through the filter unit was 11013. The average number of ultrafine particles that passed through the filter unit in the examples was 0.969 times the average number of ultrafine particles that passed through the filter unit in the comparative example, and an improvement in collection rate of about 3% was confirmed. ..

In the embodiment, when the wind speed at the central portion is 0.8 m / s, the central portion (first collection region R1) of the filter unit is deformed as described above, so that the wind speed passes through the filter unit. The wind speed at the center was 0.67 m / s, and the wind speed at the ends was 0.71 m / s. In this way, the wind speed of the airflow F passing through the filter unit was substantially averaged as a whole, and the wind speed of the airflow F passing through the filter unit was 0.69 m / s. At this time, the number of ultrafine particles that passed through the central portion (first collection region R1) of the filter unit was 10671, and the number of ultrafine particles that passed through the end portion (second collection region R2) of the filter unit. Was 18280. On average, the number of ultrafine particles that passed through the filter unit was 22167. The average number of ultrafine particles that passed through the filter unit in the examples was 0.904 times the average number of ultrafine particles that passed through the filter unit in the comparative example, and an improvement in collection rate of about 10% was confirmed. ..

As described above, it has been experimentally confirmed that the dust collection efficiency can be improved by using the filter unit according to the first embodiment.

In the above-described first to sixth embodiments, when the gas passes through the filter portion, the second surfaces 81b facing each other across the mountain portion P1 in the first collection region R1 come into contact with each other on the mountain portion P1 side. When deformed to, the ventilation resistance of the first collection region R1 is orthogonal to both sides of the first collection region R1 in the first direction DR1 parallel to the ridgeline direction of the mountain portion P1 and to the first direction DR1. The second collection region R2 of the filter medium 81 has a structure in which the filter portion is configured so as to be larger than the ventilation resistance of the second collection region R2 located on each side of the first collection region R1 in the direction DR2. Although the case where the reinforcing member 85 is provided in the above is illustrated and described, the present invention is not limited to this.

For example, as a first modification, the distance between the adjacent mountain portions P1 in the first collection region R1 is different from the distance between the adjacent mountain portions P1 in the second collection region R2. May be good. In this case, within a range not deviating from the gist of the present invention, the distance between the mountain portions P1 adjacent to each other in the first collection region R1 is larger than the distance between the mountain portions P1 adjacent to each other in the second collection region R2. It may be large or small.

For example, as a second modification, the filter medium 81 of the portion constituting the first collection region R1 and the filter media 81 of the portion constituting the second collection region R2 are separate members, and the first collection region R1 is used. The strength of the filter medium 81 of the constituent portion may be lower than the strength of the filter medium 81 of the portion constituting the second collection region R2.

For example, as a third modification, the thickness of the filter medium 81 in the first collection region R1 may be smaller than the thickness of the filter medium 81 in the second collection region R2.

As described above, the embodiments and examples invented this time are exemplary in all respects and are not limiting. The scope of the present invention is indicated by the claims and includes all modifications within the meaning and scope equivalent to the claims.

1C, 1K, 1M, 1Y image forming unit, 10 photoconductor, 11 charging device, 12 exposure device, 13 developing device, 14 developing roller, 15C, 15K, 15M, 15Y toner bottle, 17 cleaning device, 30 intermediate transfer belt, 31 Primary transfer roller, 33 Secondary transfer roller, 37 Cassette, 38 Driven roller, 39 Drive roller, 40 Timing roller, 41 Conveyance path, 48 tray, 50 Fixing part, 51 Cover member, 51A 1st cover part, 51B 2nd Cover part, 52 fixing device, 53 pressurizing roller, 54 heating roller, 60, 60F exhaust duct, 60A upstream part, 60B downstream part, 60c exhaust port, 70 blower, 75 temperature detector, 80, 80A, 80B, 80C, 80D, 80E, 80X1, 80X2 filter unit, 81 filter medium, 81a first surface, 81b second surface, 82 coarse layer, 83 dense layer, 84 frame, 85, 85A reinforcing member, 90 housing, 100, 100B, 100F Image forming device, 101 control device, 601A, 601B suction port, 800, 800D, 800E filter unit.

Claims (14)

A filter unit installed in the air passage that collects foreign matter contained in the gas flowing through the air passage.
A filter unit including at least one or more pleated filter media provided so as to have peaks and valleys alternately continuous is provided.
The filter medium includes a first surface located on the upstream side and a second surface located on the downstream side in the gas blowing direction, and is arranged so that the mountain portion is located on the upstream side.
The filter unit includes a first collection area and a second collection area surrounding the first collection area.
When the gas passes through the filter portion and is deformed so that the second surfaces facing each other across the mountain portion in the first collection region are in contact with each other on the mountain portion side, the first collection region Ventilation resistance is applied to both sides of the first collection region in the first direction parallel to the ridgeline direction of the mountain portion and both sides of the first collection region in the second direction orthogonal to the first direction. A filter unit in which the filter unit is configured to be larger than the ventilation resistance of the second collection region located. The filter unit includes a plurality of the filter media arranged in a matrix.
The plurality of filter media includes a plurality of outer edge defining filter media that define the outer edge of the first collection region.
Each of the plurality of outer edge defined filter media is provided at an end portion near the center of the filter portion, and is assembled to form at least a part of the first collection region, and a divided first collection region. It includes a divided second collection region provided on the end side far from the center of the filter portion and forming at least a part of the second collection region by gathering.
The filter unit according to claim 1, wherein the outer edge of the first collection region is defined by the continuation of the divided first collection region of the plurality of outer edge regulation filter media. The filter unit includes a plurality of the filter media arranged in a matrix.
The first collection region is composed of one or more of the filter media arranged in the central portion of the filter portion.
The filter unit according to claim 1, wherein the second collection region is composed of a plurality of other filter media arranged so as to surround the one or more filter media. The second collection region according to any one of claims 1 to 3, wherein a plurality of reinforcing members extending in a direction intersecting the first direction and reinforcing the filter medium are provided. Filter unit. The plurality of reinforcing members extend along the second direction, and the plurality of reinforcing members extend along the second direction.
4. The reinforcing member located on both ends of the first collection region in the first direction is longer than the reinforcing member located on both ends of the first collection region in the second direction. The filter unit described. The filter unit according to claim 4 or 5, wherein each of the plurality of reinforcing members has a comb-tooth shape that fits into the filter medium. The distance between the mountain portions adjacent to each other in the first collection region is different from the distance between the mountain portions adjacent to each other in the second collection region, according to any one of claims 1 to 3. Filter unit. The filter medium in the portion constituting the first collection region and the filter media in the portion constituting the second collection region are separate members.
The filter according to any one of claims 1 to 3, wherein the strength of the filter medium in the portion constituting the first collection region is lower than the strength of the filter medium in the portion constituting the second collection region. unit. The filter unit according to any one of claims 1 to 3, wherein the thickness of the filter medium in the first collection region is thinner than the thickness of the filter medium in the second collection region. The filter unit according to any one of claims 1 to 9, wherein the first collection region has a rectangular shape, a circular shape, or an oval shape when viewed from the gas blowing direction. The filter unit according to any one of claims 1 to 10, and the filter unit.
It is provided with a housing that houses the image forming part inside.
Discharging the air of the enclosure to the outside of the housing through the filter unit, the image forming apparatus. The fixing portion arranged in the housing and
Further provided with an exhaust path for discharging air containing ultrafine particles generated in the fixing portion to the outside of the housing.
The image forming apparatus according to claim 11, wherein the filter unit is arranged in the exhaust path. A blower that blows air containing ultrafine particles generated in the fixing portion so as to be discharged to the outside of the housing through the exhaust path.
The image forming apparatus according to claim 12, further comprising a control unit for changing the output of the blower. A temperature detection unit for detecting the fixing temperature in the fixing unit is further provided.
13 The image forming apparatus according to the description.

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