JP2011017895A - Image forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve the problem that a honeycomb filter and a pleats filter are expensive due to the complicated structures, it is difficult to mount a large size filter on a copying machine, whose volume is limited, in order to increase an air passing area (filter cross part) so as to enhance a VOC removing ability, and noise generated inside an apparatus (especially from driving parts on the backside of the apparatus) leaks to the outside through an exterior wall of the apparatus.SOLUTION: The image forming apparatus has a plate state filter of a large area arranged along the exterior wall inside a duct that is formed along the exterior wall of the apparatus. Since the area of the filter is large, both improvement in the removing ability of the filter and reduction of loss in pressure are obtained at the same time. Furthermore, the plate state filter is inexpensive due to a simpler structure compared with a honeycomb type.

Description

  The present invention relates to an apparatus for removing VOC (volatile organic compound) generated in an image forming apparatus such as a copying machine or a printer.

  An image forming apparatus such as a copying machine or a printer transfers toner or ink onto a recording sheet and discharges it outside the apparatus. Then, an electrophotographic image forming apparatus that transfers toner onto a sheet of paper is configured such that the toner is transferred while nipping and transporting the sheet of paper to which the toner has been transferred at a contact portion between a heating roller having a heater and a pressure roller. Use a heat fixing device that heat-fixes on paper.

  Here, since the heating roller of the heat fixing device is heated to nearly 200 ° C., a very small amount of the heat fixing device may be generated to the extent that the so-called VOC is not affected. VOC is an abbreviation for English translation of volatile organic compounds, and familiar examples include substances such as alcohol, toluene, benzene, and styrene. In other words, VOC is a generic name for organic compounds having volatile properties. An example of VOC generated from a heat fixing device is methyl mercaptan generated from silicone oil used in a heating roller (see Patent Document 1). Further, styrene may be generated from the heat fixing device and the resin material in the vicinity thereof. Furthermore, silicon rubber used in the rubber portion of the heat roller of the heat fixing device may generate benzene. Silicone oil, silicone rubber, and resin materials hardly generate VOC at room temperature, but when heated, some of the components are vaporized (or VOC contained in the form of microbubbles in the material expands). , Generates a very small amount of VOC.

As described above, since such VOC is a very small amount that does not affect the human body, it is not particularly problematic, but it is more preferable not to discharge even a very small amount. The aforementioned methyl mercaptan is the former, and styrene and benzene are the latter. In particular, benzene has a low regulatory value and is prone to problems. Therefore, a configuration has been proposed in which a filter is provided in the image forming apparatus to remove VOC (see Patent Document 1).
The schematic configuration of the color laser printer 75 provided with a filter 91 for removing VOC in the vicinity of the thermal fixing device 79 will be described below with reference to FIG.

  The color laser printer 75 includes a belt-shaped photoconductor 84 that is spanned by a plurality of pulleys and rotates at a constant speed in the direction of the arrow, a transfer drum 80 that is arranged in partial contact with the photoconductor 84, and the photoconductor 84. A charger 83 for uniformly charging the surface, an exposure device 85 for exposing the surface of the uniformly charged photoreceptor 84 to form an electrostatic latent image on the surface, and developing the electrostatic latent image Four developing devices 76a to 76d that form toner images, a transfer roller 77 that transfers the toner images to the paper, a static eliminator 78 that peels the paper from the transfer drum 80, and a heat fixing device 79 that heat-fixes the paper. It consists of. As shown in FIG. 6, the heat fixing device 79 includes a heating roller 81 and a pressure roller 82, and an oil application unit 93 including a silicone oil tank 92 is disposed on the side of the heating roller 81.

  The silicone oil of this example is a mercapto-modified silicone oil, and has a property that a mercapto group volatilizes into methyl mercaptan (CH 3 -SH) by heat and volatilizes to give off an odor (see Patent Document 1). Therefore, as shown in FIGS. 9 and 10, the color laser printer of this example is provided with a filter 91 and a fan 90 above the heat fixing device 79, and is generated from styrene and silicon rubber generated from the volatile component of silicone oil and resin. Benzene is purified by a filter 91.

  5 to 8 show conventionally proposed filters. FIG. 5 shows a pleated filter composed of a bowl-shaped filter material 71 (FIG. 6A) carrying a VOC treatment agent (adsorbent, catalyst). FIG. 7 shows a honeycomb filter in which corrugated members 72 (FIG. 6B) and flat plates are laminated. While air passes through a large number of air holes, a treatment agent (adsorbent, catalyst) applied to the wall surfaces of the holes is shown. Remove the VOC. FIG. 8 shows the structure of a filter medium used for a pleated filter. The filter medium is composed of two breathable nonwoven fabrics 95 and activated carbon particles 94 sandwiched between them. The pre-treatment air 96 containing VOC is removed from the VOC while passing through the activated carbon grains 94 to become clean air 97. The pleated filter has a feature that the processing capacity can be easily improved by increasing the passage area of the processing air, and the honeycomb filter has a feature that the ventilation resistance of the processing air can be kept low. An optimum type of filter used in an image forming apparatus such as a copying machine is selected in consideration of these characteristics.

  However, the above-described honeycomb filter and pleated filter are expensive because they have a slightly complicated structure. Further, in order to obtain a high VOC removal capability, the honeycomb filter must have fine eyes (fine pitch of the air holes). However, if the eyes are narrowed, the pressure loss of the filter also increases and the air volume is reduced. However, if the fan power is increased to secure the air volume, the next problem is noise.

  On the other hand, the pleated filter increases the area of the pleated surface and improves the filter performance (the air velocity of the air passing through the pleated surface decreases as the area increases, so activated carbon can reliably collect VOC and at the same time the pressure loss decreases. In order to achieve this, in addition to increasing the number of pleat folds, the fold height is increased. However, even if it does in that way, since it becomes difficult for air to pass through a pleat bending part, a performance increase is limited.

  Therefore, the only way to increase the VOC removal capability of the filter while suppressing the pressure loss of the filter is to increase the air passage area (that is, the filter cross-sectional area). However, it is difficult to mount a large filter in a copying machine with a limited volume.

  Further, in the image forming apparatus such as the color printer of this example, not only the noise of the fan but also the noise generated from the internal drive mechanism is often a problem. Here, since the filter material of the pleated filter has a porous structure in which activated carbon particles are filled between flexible nonwoven fabrics, it has a sound absorbing effect on noise. In addition, the honeycomb filter has an effect of absorbing noise in the process in which sound waves propagate through the fine ventilation holes. However, the filter 91 in this example only absorbs the noise of the fan 90 and cannot reduce the noise generated from the internal drive mechanism.

JP-A-11-161122

  The conventional VOC removal configuration has the following problems.

  -Honeycomb filters and pleated filters are expensive due to their complex structure.

  In order to increase the VOC removal capability of the honeycomb filter and the pleated filter, the air passage area (filter cross-sectional area) must be increased. However, it is difficult to mount a large filter in a copying machine with a limited volume.

  ・ Noise generated from inside the device (especially driving parts on the back of the device) penetrates the outer wall of the device and leaks outside the device.

In order to solve the above problems, the present invention has the following configuration.
(1) At the same time that the exhaust heat air of the image forming apparatus is caused to flow through a duct formed along the outer wall, a plate filter having a VOC removal capability and a sound absorbing effect is slanted in the duct so as to be substantially horizontal to the outer wall. To remove VOC in exhaust heat air. Further, a plate filter is disposed so as to block between the noise source inside the image forming apparatus and the outer wall of the apparatus.
(2) First locking means for locking one end of the plate filter to the outer wall side of the duct inner surface, and second locking means for locking the other end to the inner side of the duct inner surface of the apparatus. And at least one of the first locking means and the second locking means is made of an elastic member.
(3) The plate filter is disposed obliquely with respect to the flow direction of the duct, one end of the plate filter is on the device outer wall side of the duct inner surface, and the other end is on the device inner side of the duct inner surface. So that the other end is located in the vicinity of the noise source.
(4) While fixing the said plate-like filter to the apparatus outer wall side of the said duct inner surface, the said other end part of the said plate-like filter and the said duct inner surface were made to contact through an elastic member.

The configuration according to the present invention has the following effects.
(1) By installing a plate-like filter obliquely inside a duct formed along the outer wall of the image forming apparatus, it is possible to install a large area filter having approximately the same size as the outer wall area of the apparatus. Therefore, the image forming apparatus has a high VOC removal capability, and at the same time the filter structure is simplified and inexpensive. Further, noise generated from a noise source inside the image forming apparatus is absorbed by a plate filter, and the image forming apparatus can be reduced in noise. Further, since the plate-like filter does not have a bent portion unlike the pleated type filter of the conventional example, air can be uniformly flowed over the entire surface of the filter.
(2) By configuring the end of the plate filter with an elastic member, noise transmission through the plate filter can be reduced and noise can be reduced.
(3) While arrange | positioning a plate-shaped filter diagonally in a duct, the edge part of the plate-shaped filter was made to contact | connect the inner surface of a duct inside an apparatus, and the noise source vicinity. By bringing the plate filter closer to the noise source, the sound absorption effect by the plate filter can be enhanced and the noise can be reduced.
(4) The plate-like filter is fixed to the inner surface of the duct on the outer wall side of the device, and the noise transmission through the plate-like filter is reduced by bringing the end of the plate-like filter into contact with the inner surface of the duct via an elastic member. And noise can be reduced.

Copying machine according to the first embodiment (front sectional view) Copier of the first embodiment Explanation of sound wave propagation Copying machine of second embodiment (right side sectional view) Pleated filter Wavy member constituting honeycomb filter Honeycomb filter Filter media structure Conventional color laser printer Conventional heat fixing device

(First embodiment)
Hereinafter, a first embodiment to which the present invention is applied will be described with reference to FIGS. 1 is a front sectional view of a copying machine 30 according to the present invention, FIG. 2a is a right side sectional view of the copying machine 30, and FIG. 2b is a perspective view. The configuration will be described below with reference to the drawings.

  The copying machine 30 in FIG. 1 includes a reader unit 32, a paper feeding unit 50, a printing unit 24, and a thermal fixing device 25. The copying machine 30 sends the paper 50 of the paper feed unit 31 to the printing unit 24, prints the original image read by the reader unit 32 as a toner image on the paper, and then fixes and discharges it with the thermal fixing device 25. The thermal fixing device 25 includes a heating roller provided with a heater and a pressure roller pressed against the heating roller. Further, a silicon rubber layer is provided on the surface of the heating roller and the pressure roller to increase the contact area of the roller nip portion. In this configuration, the sheet 50 separated into one sheet by the sheet feeding unit 31 is sent to the stopped registration roller pair 9 and 10 via the sheet detection unit 11. The controller 40 (see FIG. 3) of the image forming apparatus stops the sheet conveyance operation based on the sheet detection timing in the sheet detection unit 11 and sets a loop for correcting skew feeding before the registration rollers 9 and 10. To form. Next, a controller (not shown) of the image forming apparatus waits for the preparation of the printing unit 24, rotates the pair of registration rollers 9 and 10, and sends the paper 50 to the printing unit 24. The paper 50 onto which the toner image has been transferred by the printing unit 24 is conveyed to the thermal fixing device 25, where the toner image is fixed at the pressure nip portion between the heating roller and the pressure roller, and then discharged outside the apparatus.

  The right side cross-sectional view of FIG. 2a shows the exhaust heat mechanism of the copying machine 30 and the exhaust VOC removal mechanism. FIG. 2b is a perspective view of the VOC removal mechanism. Hot air around the heat fixing device 25 is pulled by the suction force of the fan 3 and introduced into the duct 5. The air in the duct 5 is discharged out of the machine by the fan 3 via the plate-like filter 1. The filter 1 is made of the same material as the filter medium shown in FIG. In the case of this example, the drive mechanism 8 of the paper feeding unit 50 is a main noise generation source, but the noise generated by the drive mechanism 8 is absorbed by the filter 1 to reduce the noise leaking outside the copying machine. Further, as shown in FIG. 2b, the filter 1 covers the back surface of the copying machine in a wide range. Further, one end of the filter 1 is locked to the duct inner surface outer wall side 5b by the first locking means 4a, and the other end is locked to the duct inner surface inner side 5a by the second locking means 4b. The first locking means 4a and the second locking means 4b are made of a rubber material so that vibrations inside the apparatus are not transmitted to the outer wall of the apparatus via the filter 1.

According to this embodiment of the above configuration and operation, the following effects can be obtained.
(1) By installing a plate-like filter obliquely inside a duct formed along the outer wall of the image forming apparatus, it is possible to install a large area filter having approximately the same size as the outer wall area of the apparatus. Therefore, the image forming apparatus has a high VOC removal capability (the air velocity of the air passing through the filter decreases as the filter area increases, and the activated carbon reliably catches VOC). At the same time, the filter structure is simplified and inexpensive. Become. Further, the noise generated from the drive mechanism 8 is absorbed by the plate filter, and the noise of the image forming apparatus can be reduced. Furthermore, since the filter 1 of the present embodiment does not have a bent portion unlike the pleated filter of the conventional example, air can flow uniformly over the entire surface of the filter, and the entire surface of the filter can be effectively utilized.
(2) The first locking means 4a and the second locking means 4b are made of a rubber material so that vibrations inside the apparatus are not transmitted to the outer wall of the apparatus via the filter 1.
(3) The position of the second locking means 4b is in the vicinity of the drive mechanism 8 serving as a noise source. Therefore, the filter 1 is positioned in the vicinity of the drive mechanism 8, effectively absorbing noise generated from the drive mechanism 8, and reducing the noise of the copying machine 30.

  FIG. 3 shows how the sound wave passing through the filter 1 is attenuated. The sound wave Sin (sound wave emitted from the drive mechanism 8) incident on the inner surface 5a of the duct wall surface is absorbed by the filter 1 and becomes the attenuated sound wave Sout. Here, as a general theory, it is known that the effect of the sound absorbing material increases as the sound wave energy increases. In the example of FIG. 3, since the filter 1 is closer to the sound source (driving mechanism 8), the sound wave energy incident on the filter 1 becomes high (the sound wave energy is attenuated in the air when it is away from the sound source). The sound wave Sout that has passed through the filter 1 is partially reflected by the device outer wall side surface 5 b of the duct wall surface and absorbed by the filter 1. At this time, since the sound wave energy is attenuated in the air as the apparatus outer wall side surface 5b of the duct wall surface is separated from the filter 1, the reflected sound wave Sreflect can be reliably absorbed by the filter 1. As described above, noise reduction can be realized by bringing the filter 1 closer to the drive mechanism 8.

  FIG. 2 c shows a state in which the filter 1 is made closer to the drive mechanism 8 by making the filter 1 into a bow shape. In the example of FIG. 2c, noise generated from the drive mechanism 8 can be absorbed more effectively.

  The filter configuration of this embodiment is intended to remove VOC, but may be used to remove ozone and scattered toner released from the charging unit of the printing unit. The activated carbon constituting the filter 1 can also adsorb ozone, and the nonwoven fabric can collect the scattered toner. When electrostatic treatment is applied to the nonwoven fabric, the collection efficiency of scattered toner can be further increased.

  By the way, in order to perform ozone removal more effectively, it is necessary to apply an oxidation catalyst to the filter 1. However, it has been found that the application of an oxidation catalyst reduces the flame retardance of a filter having a large air contact area such as the filter 1. Therefore, it can be said that the filter configuration of this embodiment is suitable for removing VOCs and collecting dust such as scattered toner.

(Second embodiment)
FIG. 4 shows the filter 1 supported by triangular ribs 6. At the same time as supporting the filter 1 on the apparatus outer wall side 5b on the inner surface of the duct, the filter 1 is in contact with the apparatus inner side 2 on the inner surface of the duct via the elastic member 6b. With this configuration, the present embodiment can reduce the transmission of vibration to the outer wall via the filter 1 and reduce noise.

DESCRIPTION OF SYMBOLS 1 Filter 3 Fan 4a 1st latching means 4b 2nd latching means 5 Duct 6 Rib 8 Drive mechanism

Claims (5)

In the device provided with an air flow formed so as to flow in the horizontal direction with the outer wall surface in the vicinity of the outer wall of the device, and a noise source inside,
A plate-like filter that is arranged so as to block the air flow and has a sound absorbing effect while removing a predetermined substance contained in the air;
The apparatus is characterized in that the plate-like filter is disposed horizontally with the outer wall and between the noise source and the outer wall. A duct constituting the air flow;
First locking means for locking one end of the plate filter to the outer wall side of the duct inner surface;
A second locking means for locking the other end of the inner surface of the duct to the inside of the device;
An apparatus in which the plate filter is disposed so as to be inclined with respect to the air flow direction and in a direction perpendicular to the outer wall surface of the apparatus,
2. The apparatus according to claim 1, wherein at least one of the first locking means and the second locking means is constituted by an elastic member.   The apparatus according to claim 1 or 2, wherein the other end is disposed in the vicinity of the noise source.   3. The plate filter is fixed to the outer wall side of the duct inner surface, and the other end of the plate filter and the duct inner surface are brought into contact with each other through an elastic member. 3. The apparatus according to 3.   5. The image forming apparatus according to claim 1, wherein the plate-like filter is a three-layer structure filter in which an activated carbon layer is provided between two nonwoven fabrics.

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