JP6341445B2 - Image forming apparatus - Google Patents

Description

  The present invention relates to an image forming apparatus having a sound absorbing device using a Helmholtz resonator.

（Δｒ：開口端補正） In an electrophotographic image forming apparatus, driving sounds of various driving units and sounds when a polygon mirror rotates are generated during image formation. As a configuration capable of absorbing sound generated during image formation, Patent Documents 1 and 2 describe an image forming apparatus having a sound absorption device using a Helmholtz resonator.
The Helmholtz resonator is formed by a hollow portion having a certain volume and a communication portion that communicates the hollow portion with the outside. When the volume of the cavity is “V”, the opening area of the communication part is “S”, the length of the communication part in the communication direction is “H”, and the sound velocity is “c”, the sound absorption using the Helmholtz resonator is performed. The frequency “f” of the sound absorbed by the device is obtained by the following equation (1).

(Δr: Open end correction)

  In the image forming apparatus described in Patent Document 1, the exterior cover fixed to the casing of the apparatus has a double structure, and the space between the two exterior members forming the double structure is partitioned by ribs, A cavity of the above-described Helmholtz resonator is formed. Furthermore, the communication part of the Helmholtz resonator mentioned above is formed by providing a hole in the inner exterior member of the two exterior members, and the sound generated from the inside of the apparatus can be absorbed.

  Some image forming apparatuses include an exterior opening / closing cover that is openable and closable with respect to the apparatus main body so that the consumables to be replaced are exposed when the user replaces consumables such as toner bottles and process cartridges. Such an exterior opening / closing cover is often provided on the side surface of the image forming apparatus facing the user who operates the operation unit of the image forming apparatus. And if the sound inside the apparatus leaks from the side facing the user, it tends to be a noise that makes the user uncomfortable.

  As a configuration for suppressing sound from leaking from the surface provided with the exterior opening / closing cover in the image forming apparatus, it is conceivable to provide a sound absorbing device similar to the above-mentioned Patent Document 1 in the exterior opening / closing cover constituting a part of the exterior cover. . However, when the hollow part of the Helmholtz resonator described above is formed with a double structure of the exterior opening / closing cover, the exterior opening / closing cover becomes heavy, leading to a decrease in operability of the opening / closing operation. In addition, if a hole is formed in the exterior member inside the exterior opening / closing cover having a double structure to form the communication part of the Helmholtz resonator described above, the communication part is exposed when the exterior opening / closing cover is opened. When this communication part is exposed, there is a possibility that the sound absorption effect is reduced due to foreign matter entering the cavity or the communication part, or the sound absorption effect is reduced due to the contact part being damaged by the user. For this reason, it is not desirable to provide the exterior opening / closing cover with a sound absorbing device similar to that of Patent Document 1.

  The present invention has been made in view of the above-mentioned problems, and the object thereof is as follows. That is, to provide an image forming apparatus capable of suppressing sound leakage from the surface provided with the exterior opening / closing cover while suppressing deterioration in operability of the exterior opening / closing cover and exposure of the communication portion of the Helmholtz resonator. It is.

In order to achieve the above object, according to the first aspect of the present invention, in the image forming apparatus having the sound absorbing device using the Helmholtz resonator, the outer surface is opened by opening the exterior opening / closing cover that can be opened and closed with respect to the apparatus main body. the inner surface of the interior cover to expose provided with the sound-absorbing device, and space to be outward from the wall portion forming the wall surface of the cavity of the Helmholtz resonator in the inner space of the interior cover, the outside of the interior cover It has an interior cover through hole that penetrates the interior cover so as to communicate with the space .

  According to the present invention, it is possible to suppress the leakage of sound from the surface provided with the exterior opening / closing cover while suppressing the deterioration of the operability of the exterior opening / closing cover and the exposure of the communication part of the Helmholtz resonator. effective.

FIG. 3 is an explanatory view of a mounting position of a sound absorbing device in a copying machine according to the present invention, FIG. Explanatory drawing of an attachment position. 1 is a schematic configuration diagram of a copying machine according to an embodiment of the present invention. FIG. 2 is a schematic configuration diagram in the vicinity of a photoconductor in the copier. FIG. 2 is a perspective view of the copying machine with a left side exterior cover removed from the state shown in FIG. FIG. 5 is an explanatory perspective view of the copier in the state of FIG. 4 as seen from an angle at which an inner surface of the front housing to which the front inner cover is fixed is visible. The expansion perspective view of a sound absorption device. The schematic sectional drawing of the state which attached the sound-absorbing apparatus to the front inner cover. The schematic diagram of the sound-absorbing device using a Helmholtz resonator. Explanatory drawing of the structure which provided the sound-absorbing device integrally with the inner cover. Explanatory drawing of the structure which forms a sound-absorbing device with the rib and the sound-absorbing cover member which were formed integrally with the inner cover. Explanatory drawing of the structure which provided the through-hole in the inner cover which has arrange | positioned several sound-absorbing apparatuses, (a) is the top view which showed typically the positional relationship of an inner cover and a laser writing apparatus, (b), The front view of the inner cover which provided the through-hole. The top view which showed typically the state which cleans the glass member of a laser writing apparatus with the structure shown in FIG.

  Hereinafter, an embodiment of an electrophotographic copying machine (hereinafter simply referred to as “copying machine 500”) as an image forming apparatus to which the present invention is applied will be described. In this embodiment, a monochrome image forming apparatus will be described as an example of the copying machine 500, but the present invention can be similarly applied to a known color image forming apparatus.

First, the configuration of the copying machine 500 will be described.
FIG. 2 is a schematic configuration diagram of the entire copying machine 500 according to the present embodiment. In FIG. 2, the image reading apparatus 200 is mounted on the copying machine main body 100 of the copying machine 500, and the copying machine main body 100 is placed on a recording paper bank 300. Mounted on the image reading apparatus 200 is an automatic document feeder 400 that is configured to be rotatable about the back side (the back side in the drawing) as a fulcrum.

  Inside the copying machine main body 100, a drum-shaped photoconductor 10 is provided as a latent image carrier. FIG. 3 is a schematic configuration diagram in which the vicinity of the photoconductor 10 is enlarged. As shown in FIG. 3, around the photosensitive member 10, a static elimination lamp 9, a charging device 11 using a charging roller, a developing device 12, a transfer unit 13, and a cleaning device 14 having a photosensitive member cleaning blade 8 are arranged. Yes. The developing device 12 uses a polymerized toner produced by a polymerization method as a toner, and attaches the polymerized toner to an electrostatic latent image on the photoconductor 10 using a developing roller 121 as a developer carrier. Visualize.

  The transfer unit 13 includes a transfer belt 17 wound around two roller members, a first belt stretching roller 15 and a second belt stretching roller 16, and the transfer belt 17 is photosensitive at the transfer position B. It is pressed against the peripheral surface of the body 10.

  Foreign matter such as residual toner and paper dust remaining on the transfer belt 17 after the recording paper P is separated is transferred to the first belt stretching roller 15 via the transfer belt 17 provided in the transfer belt cleaning unit C. Then, the cleaning blade 18 is scraped off.

  Further, the copying machine main body 100 is provided with a toner replenishing device 20 for replenishing the developing device 12 with new toner on the left side of the charging device 11 and the cleaning device 14 in the drawing.

  Further, the copying machine main body 100 is provided with a recording paper transport device 60 that transports the recording paper P sent from the recording paper cassette 61 of the recording paper bank 300 to the discharge stack section 39 via the transfer position B. The recording paper transport device 60 transports the recording paper P along the supply path R1 or the manual feed path R2 and the recording paper transport path R. On the recording paper conveyance path R, a registration roller pair 21 is provided upstream of the transfer position B in the recording paper conveyance direction.

  On the other hand, a thermal fixing device 22 is provided on the downstream side in the recording paper conveyance direction of the recording paper conveyance path R with respect to the transfer position B. The heat fixing device 22 performs heat and pressure fixing by sandwiching the recording paper P between a heating roller 30 as a heating member and a pressure roller 32 as a pressure member.

  A discharge branch claw 34, a discharge roller 35, a first pressure roller 36, a second pressure roller 37, and a roller 38 with a stiffness are provided further downstream in the recording paper conveyance direction of the heat fixing device 22. In addition, a discharge stack unit 39 for stacking the recording paper P on which the image has been formed through the heat fixing device 22 is also provided.

  Further, the copying machine main body 100 is provided with a switchback device 42 on the right side in the drawing. The switchback device 42 reverses the reversing path R3 branched from the position where the discharge branch claw 34 of the recording paper transport path R is disposed, and the recording paper P passing through the reversing path R3 again. The recording paper P is conveyed along a re-conveying path R4 that leads to the position of the roller pair 21. A switchback roller pair 43 is provided in the reverse path R3, and a plurality of recording paper transport roller pairs 66 are provided in the re-transport path R4.

  As shown in FIG. 2, the copying machine main body 100 is provided with a laser writing device 47 on the left side of the developing device 12 in the drawing. The laser writing device 47 includes a scanning optical system such as a laser light source (not shown), a polygon mirror 48 that is a rotating polygon mirror for scanning, a polygon motor 49, and an fθ lens (not shown).

The image reading apparatus 200 includes a light source 53, a plurality of mirrors 54, an imaging optical lens 55, an image sensor 56 such as a CCD image sensor, and the like, and a contact glass 57 is provided on the upper surface thereof.
The automatic document feeder 400 is provided with a document setting table (not shown), and a document stacking table (not shown) is provided at the document discharge position. The automatic document conveying device 400 includes a plurality of document conveying rollers (not shown), and the document is conveyed by the document conveying rollers from the document setting table to the reading position on the contact glass 57 of the image reading device 200 (not shown). It is conveyed to the document stacking table.

  In the recording paper bank 300, a plurality of recording paper cassettes 61 for storing recording paper P such as paper or OHP film as recording materials are provided. Each recording paper cassette 61 is provided with a call roller 62, a supply roller 63, and a separation roller 64, respectively. On the right side of the recording paper cassette 61 in the drawing, the above-described supply path R1 leading to the recording paper conveyance path R of the copying machine main body 100 is formed. This supply path R1 is also provided with several recording paper transport roller pairs 66 for transporting the recording paper P.

  The copying machine main body 100 is provided with a manual paper feed unit 68 on the right side in FIG. The manual feed unit 68 is provided with a manual feed tray 67 that can be opened and closed. The manual feed path R2 that guides the recording paper P set on the manual feed tray 67 to the recording paper transport path R is formed. ing. Similarly to the recording paper cassette 61, the manual paper feeding unit 68 is also provided with a calling roller 62, a supply roller 63, and a separation roller 64.

Next, the operation of the copying machine 500 will be described.
When copying using the copying machine 500, first, a main switch (not shown) is turned on, and a document is set on a document setting table of the automatic document feeder 400. In the case of a book document, the automatic document feeder 400 is opened, a document is set directly on the contact glass 57 of the image reading device 200, and the automatic document feeder 400 is closed and pressed.

Thereafter, when a start switch (not shown) is pressed, when an original is set on the automatic document feeder 400, the original is moved onto the contact glass 57 through the document feeding path by the document feeding roller, and then the image reading device 200 is driven. To do. The original content is read and discharged onto the original stack table. On the other hand, when the document is set directly on the contact glass 57, the image reading device 200 is immediately driven to read the content of the document.
When reading the content of the original, the image reading apparatus 200 irradiates the original surface on the contact glass 57 with light from the light source 53 while moving the light source 53 along the contact glass 57. Then, the reflected light is guided to the imaging optical lens 55 by a plurality of mirrors 54 and put into the image sensor 56, and the document content is read by the image sensor 56.

  In the copying machine 500, the photosensitive member 10 is rotated by a photosensitive member driving motor (not shown) at the same time as reading the document content. First, the charging device 11 uniformly charges the surface of the photoconductor 10 to about −1000 [V], for example. Next, laser writing is performed by irradiating the photosensitive member 10 with laser light from the laser writing device 47 in accordance with the content of the original read by the image reading device 200 described above, thereby forming an electrostatic latent image on the surface of the photosensitive member 10. The surface potential of the portion irradiated with the laser light (latent image portion) is, for example, 0 [V] to −200 [V]. Thereafter, the developing device 12 attaches toner to the electrostatic latent image to make it visible.

  In the copying machine 500, at the same time when the start switch is pressed, the recording paper P is sent out by the calling roller 62 from the one corresponding to the selected size among the plurality of recording paper cassettes 61 provided in the recording paper bank 300. Then, the fed recording sheet P is separated one by one by the supply roller 63 and the separation roller 64, and the one sheet is guided to the supply path R 1, and is guided to the recording sheet conveyance path R by the recording sheet conveyance roller pair 66. . The recording paper P conveyed to the recording paper conveyance path R hits the registration roller pair 21 and is stopped.

When the manual paper feed unit 68 is used, the manual feed tray 67 is opened and the recording paper P is set thereon. Also in this case, the recording paper P is transported to the manual feed path R2 by the calling roller 62, the supply roller 63, and the separation roller 64, and is guided to the recording paper transport path R by the recording paper transport roller pair 66. It stops against the registration roller pair 21.
In this way, the recording paper P stopped by the registration roller pair 21 starts to rotate at the timing when the leading edge of the visible toner image of the photoreceptor 10 enters the transfer position B. The pair 21 is sent to the transfer position B.

  The recording paper P fed to the transfer position B is transferred with the toner image on the photoreceptor 10 by the transfer unit 13 and carries the toner image on the surface thereof. The residual toner remaining on the surface of the photoreceptor 10 after the transfer is removed by the cleaning device 14, and the residual potential on the photoreceptor 10 is also removed by the charge eliminating lamp 9. By removing the residual potential, the surface potential is averaged to a reference potential of 0 [V] to −150 [V], and is prepared for the next image formation starting from the charging device 11.

  On the other hand, the recording paper P carrying the toner image is conveyed by the transfer belt 17 and enters the heat fixing device 22. Then, heat and pressure are applied while being conveyed between the heating roller 30 and the pressure roller 32, and the toner image on the recording paper P is fixed. Thereafter, the recording paper P is stiffened by the discharge roller 35, the first pressure roller 36, the second pressure roller 37, and the roller 38 with a stiffness, discharged onto the discharge stack portion 39, and stacked there. .

  When images are to be formed on both sides of the recording paper P, the discharge branch claw 34 is switched, the toner image is transferred and fixed on one side of the recording paper P, and then the recording paper P is removed from the recording paper conveyance path R. Enter in reverse path R3. The recording paper P put in the reversing path R3 is transported by the recording paper transport roller pair 66 and put into the switchback position 44, and then switched back by the switchback roller pair 43, and this time is put in the re-transporting path R4 and recorded. The paper transport roller pair 66 guides the recording paper transport path R again. Then, the toner image is transferred to the opposite surface of the recording paper P that has passed through the re-transport path R4 in the same manner as described above.

Next, features of the present invention will be described.
FIG. 1 is an explanatory diagram of the mounting position of the sound absorbing device 600 in the copying machine 500. FIG. 1A is a perspective explanatory view showing a state in which the front cover 101 of the copying machine 500 is opened and the inner cover 102 is exposed, and FIG. 1B is a mounting position of the sound absorbing device 600 in the inner cover 102. It is explanatory drawing of.
The front opening / closing cover 101 is openable and closable with respect to the copying machine 500 main body, as indicated by an arrow α in FIG. The inner cover 102 is fixed to the casing of the copier 500 by screwing, and can be removed from the copier 500 by removing the screw.

  The copying machine 500 shown in FIG. 1A is in a state in which the automatic document feeder 400 and the optical system inside the image reading apparatus 200 are removed. Further, by opening the front opening / closing cover 101 which is an exterior cover, the inner cover 102 which is an interior cover is exposed. Further, a toner bottle (not shown) provided in the toner replenishing device 20 is removed, and a bottle set hole 20a, which is a portion into which the toner bottle is inserted in the inner cover 102, is opened. A recording paper cassette outer cover 61 a having a handle for pulling out the recording paper cassette 61 is disposed below the front opening / closing cover 101 in the copying machine 500.

  As shown in FIG. 1A, the copying machine 500 has a front opening / closing cover 101 that is an exterior opening / closing cover that can be opened / closed for replacement and maintenance of consumables such as toner bottles, so that the user of the apparatus can easily operate. Is provided. And as shown to Fig.1 (a), a user cannot touch the part which should not be in contact with the user inside a device to the part exposed by opening the front opening / closing cover 101. An inner cover 102 is provided.

FIG. 4 is a perspective view of the copying machine 500 in which the left side exterior cover 103 is removed from the state shown in FIG.
The inner cover 102 may be divided into several parts in consideration of the exchangeability of units inside the copying machine 500 such as the laser writing device 47 and the ease of maintenance work. In the example shown in FIG. 4, the front upper inner cover 102a and the front lower inner cover 102b are divided into two parts, and the front lower inner cover 102b in the vicinity of the laser writing device 47, which is a writing unit, is the other unit. It is a separate part from the part.

  In the example shown in FIG. 4, the inner cover 102 has two parts. However, in consideration of maintainability, replacement frequency, and the like, there is no particular problem even if the inner cover 102 is constituted by one part. Further, the unit to be subjected to sound absorption is not limited to the laser writing device 47, and any sound source may be used.

FIG. 5 is a perspective explanatory view of the copying machine 500 in the state of FIG. 4 as viewed from an angle at which the inner surface of the front case 510 provided on the inner cover 102 and to which the inner cover 102 is fixed is visible. is there.
As shown in FIG. 5, the copier 500 includes a sound absorbing device 600 using a Helmholtz resonator at a position facing the laser writing device 47 on the inner side of the front surface.
As shown in FIGS. 4 and 5, the writing device holding frame 470 which is a writing unit holding member for holding the laser writing device 47 has a front end fixed to the front casing 510 and a rear end positioned at the rear end. It is fixed to the rear housing 530.

  As shown in FIG.1 (b), the inner cover 102 is equipped with the sound absorption apparatus installation part 160 in the inner surface. Then, as indicated by an arrow β in FIG. 1B, the sound absorbing device 600 is attached and fixed to the sound absorbing device installation portion 160, and the inner cover 102 is fixed to the front housing 510. As a result, as shown in FIG. 5, the sound absorbing device 600 protrudes inward from the sound absorbing device installation opening 510 a which is an opening formed in the front casing 510.

  FIG. 6 is an enlarged perspective view of the sound absorbing device 600, and FIG. 7 is a schematic cross-sectional view of the sound absorbing device 600 attached to the inner cover 102. The sound absorbing device 600 is a sound absorbing device using a Helmholtz resonator, and includes three members, a sound absorbing main body member 610, a sound absorbing cover member 620, and a sound absorbing cap member 630, as shown in FIGS. The sound absorbing cover member 620 is fixed to the sound absorbing main body member 610 by a cover fixing screw 640, and the sound absorbing main body member 610 is fixed to the inner cover 102 by a main body fixing screw 650.

FIG. 8 is a schematic diagram of a sound absorbing device 600 using a Helmholtz resonator.
As shown in FIG. 8, the Helmholtz resonator is shaped like a container with a narrow entrance, and is constituted by a hollow portion 601 having a certain volume and a communication portion 603 smaller than the hollow portion 601. Absorbs incoming specific frequency sound.
The volume of the cavity 601 is “V”, the opening area of the opening 602 in the communication portion 603 is “S”, the length of the communication portion 603 is “H”, the sound velocity is “c”, and the sound absorption frequency in the sound absorbing device 600 is set. When “f” is assumed, the following equation (1) is established.

“Δr” in the equation (1) is an opening end correction, and “Δr = 0.6r” is generally used when the radius when the cross section of the communication portion 603 is circular is “r”.
As shown in the equation (1), the frequency of the sound absorbed by the sound absorbing device 600 can be obtained from the volume V of the hollow portion 601, the length H of the communicating portion 603, and the opening area S of the communicating portion 603.

  In the copying machine 500, various sounds such as a driving sound of a driving motor that transmits rotational driving to various rollers, a moving sound of moving members such as various rollers, and a rotating sound of the polygon mirror 48 of the laser writing device 47 are generated. . Such a sound may be transmitted to the outside of the copier 500, resulting in noise that causes discomfort to surrounding people. By forming the sound absorbing device 600 in accordance with the frequency of the sound that is desired to be suppressed from being transmitted to the outside among such sounds that can become noise, the sound absorbing device 600 can absorb the sound that can become noise.

  As shown in FIGS. 1 and 5, the copier 500 of this embodiment is an example in which a sound absorbing device 600 using a Helmholtz resonator is installed inside the inner cover 102. Of the devices that can be a noise source, when trying to obtain a sound absorption effect for the laser writing device 47, as shown in FIG. 5, it is most effective to install the sound absorption device 600 in the vicinity of the object to absorb the sound. Is.

In order to obtain a sound-absorbing effect for the sound toward the front of the copying machine 500, that is, the position where the user stands, with the sound-absorbing device 600 using the Helmholtz resonator, the sound-absorbing device 600 is provided inside the member forming the front surface of the copying machine 500. It is desirable to provide a sound absorbing device 600.
However, when the sound absorbing device 600 is provided on the front opening / closing cover 101 among the members forming the front surface, the weight of the front opening / closing cover 101 becomes heavy, and the operability during the opening / closing operation of the user is lowered. Further, when the sound absorbing device 600 is provided on the front opening / closing cover 101, the communication part 603 of the Helmholtz resonator faces the inside of the device in the front opening / closing cover 101. Therefore, when the front opening / closing cover 101 is opened, the communication part 603 is exposed. Resulting in. When the communicating portion 603 is exposed, foreign matter may enter the sound absorbing device 600 or damage may occur when the user touches the sound absorbing device 600, thereby reducing the sound absorbing effect of the sound absorbing device 600.

As shown in FIGS. 1 and 5, the copying machine 500 is provided with a sound absorbing device 600 on the inner surface of the inner cover 102 where the outer surface is exposed by opening the front opening / closing cover 101. Provided.
Since the sound absorbing device 600 is provided on the inner cover 102, the weight of the front opening / closing cover 101 is not changed even when the sound absorbing device 600 is provided on the side surface of the copying machine 500 where the front opening / closing cover 101 is provided. The operability during the opening / closing operation of the person can be maintained.
Further, since the sound absorbing device 600 is provided on the inner surface of the inner cover 102, the communication portion 603 of the sound absorbing device 600 is not exposed when the front opening / closing cover 101 is opened, and the communication portion 603 is exposed. It is possible to prevent the occurrence of the above-described problems. Specifically, it is possible to prevent foreign matter from entering the sound absorbing device 600 through the communication portion 603 or damage caused by the user touching the sound absorbing device 600, and the sound absorbing effect of the sound absorbing device 600 can be maintained. Can be made.

  Further, by providing the sound absorbing device 600 on the inner surface of the inner cover 102, it is possible to obtain a sound absorbing effect with respect to the sound toward the position where the user stands, and to suppress the generation of noise that causes discomfort to the user.

  Further, depending on the frequency of the sound to be absorbed, the volume of the hollow portion 601 increases. Therefore, if the sound absorbing device 600 is provided in the front opening / closing cover 101, the layout space of the front opening / closing cover 101 increases, and the copying machine 500 May increase in size. On the other hand, in the configuration in which the sound absorbing device 600 is provided inside the inner cover 102, the remaining space in the copying machine 500 can be used effectively, leading to a reduction in the size of the copying machine 500 including the sound absorbing device 600.

  Patent Document 2 describes a configuration including a sound absorbing device that uses a Helmholtz resonator inside the exterior cover, but the sound absorbing device is formed in the casing of the image forming apparatus inside the exterior cover. Different from the copying machine 500 of the present embodiment.

  If a sound absorbing device is formed on the housing itself of the image forming apparatus as in Patent Document 2, the sound absorbing device cannot be removed from the apparatus main body, and it is difficult to maintain the sound absorbing device and adjust the frequency of sound absorption. On the other hand, in the copying machine 500 of this embodiment, the sound absorbing device 600 is provided on the inner cover 102 that can be removed from the apparatus main body, and therefore the sound absorbing device 600 can be removed by removing the inner cover 102. Therefore, it is easy to maintain the sound absorbing device 600 and adjust the frequency of sound absorption.

  Further, when the sound absorbing device is damaged, in the configuration in which the sound absorbing device is formed in the housing itself, the housing itself needs to be replaced in order to replace the sound absorbing device. On the other hand, in the copying machine 500 of this embodiment, only the sound absorbing device 600 can be replaced by removing the inner cover 102 and removing the sound absorbing device 600. In a configuration in which at least a part of the sound absorbing device 600 is formed integrally with the inner cover 102, the sound absorbing device 600 can be replaced by replacing the inner cover 102.

  In addition, the sound absorbing device 600 included in the copying machine 500 of this embodiment is made of resin. The material forming the sound absorbing device 600 is not particularly limited, and a metal material may be used as in Patent Document 2. However, the resin material is easier to process and can improve the accuracy of parts, and the volume V of the hollow portion 601, the length H of the communicating portion 603, and the communicating portion 603 with respect to the frequency to be absorbed. Can be set to an appropriate value, and a desired sound absorbing effect can be easily obtained.

FIG. 9 is an explanatory diagram of a configuration in which a sound absorbing device 600 using a Helmholtz resonator is provided integrally with the inner cover 102.
The inner cover 102 includes a sound absorbing device 600 on the inner back surface 102r side, which is the back side of the inner front surface 102f exposed when the front opening / closing cover 101 is opened. In the configuration shown in FIG. 9, the entire sound absorbing device 600 including the rib 120 formed so as to protrude from the inner back surface 102r of the inner cover 102 and the lid portion 122 formed with the communication portion 603 is blown or welded. It is integrated with the cover 102. When the inner cover 102 and the sound absorbing device 600 are integrated, the volume of the hollow portion 601 in the sound absorbing device 600 is determined, and thus cannot be adjusted. However, there is a cost merit in reducing the number of parts and the like. If you want to, it is better to unite.

FIG. 10 is an explanatory diagram of a configuration in which the sound absorbing device 600 using the Helmholtz resonator is formed by the rib 120 and the sound absorbing cover member 620 that are formed integrally with the inner cover 102.
In the configuration shown in FIG. 10, unlike the configuration shown in FIG. 9, the sound absorbing cover member 620 in which the communication portion 603 is formed is different from the rib 120 formed so as to protrude from the inner back surface 102 r of the inner cover 102. This is the configuration. When the sound absorbing cover member 620 is a separate member, the volume of the cavity 601 in the sound absorbing device 600 can be finely adjusted by making the shape of the sound absorbing cover member 620 different. Thereby, when it is desired to change the target frequency, the sound absorbing device 600 can be tuned only by slightly correcting the shape of the sound absorbing cover member 620.
9 and 10, the rib 120 has a function of reinforcing the inner cover 102 and a function of forming the wall surface of the cavity 601 in the Helmholtz resonator.

  In FIG. 11, a plurality of sound absorbing devices 600 are arranged inside the inner cover 102 of the copying machine 500, a space T is formed between adjacent sound absorbing devices 600, and the inner cover 102 is opposed to the space T. It is explanatory drawing of the structure which provided the through-hole 102c. FIG. 11A is a top view schematically showing the positional relationship between the inner cover 102 and the laser writing device 47, and FIG. 11B is a front view of the inner cover 102 provided with a through hole 102c. .

In the configuration shown in FIG. 11, a sound absorbing device 600 is installed in the vicinity of the laser writing device 47. In the case of a configuration in which a plurality of sound absorbing devices 600 using Helmholtz resonators are arranged, if the sound absorbing devices 600 are in close contact with each other, resonance may occur and a desired sound absorbing effect may not be obtained.
In the configuration shown in FIG. 11, since the adjacent sound absorbing devices 600 are separated from each other by the space T, a desired sound absorbing effect can be obtained.

Furthermore, when the portion that becomes the space T and the glass member 47a of the laser writing device 47 are arranged in a positional relationship so as to be linear, the inner cover 102 at a position facing the space T as shown in FIG. The through-hole 102c may be provided in. By providing the through hole 102c at such a position, the glass member 47a of the laser writing device 47 can be accessed from the outside of the inner cover 102 without removing the inner cover 102.
In addition, since the through-hole 102c is provided in the inner cover 102 at a position facing the space T that is outside the portion forming the Helmholtz resonator, the influence of the sound absorption effect is reduced even in the configuration including the through-hole 102c. Can be prevented.

FIG. 12 is a top view schematically showing a state in which the glass member 47a of the laser writing device 47 is cleaned in the copying machine 500 having the configuration shown in FIG.
As shown in FIG. 12, a dedicated glass cleaning member 700 is inserted to clean the glass member 47a of the laser writing device 47 from the through hole 102c provided in the inner cover 102, and the surface of the glass member 47a is cleaned. At the tip of the glass cleaning member 700, there is a soft part for cleaning the glass, and the glass cleaning member 700 is reciprocated as indicated by an arrow γ in FIG. 12 to clean the glass member 47a.

  Further, when the copying machine 500 is in operation (the front opening / closing cover 101 provided outside the inner cover 102 is closed), the through-hole 102c provided in the inner cover 102 is an opening. Thus, the laser writing device 47 can be cooled by natural convection flowing through the gap between the inner cover 102 and the front opening / closing cover 101.

What has been described above is merely an example, and the present invention has a specific effect for each of the following modes.
(Aspect A)
In an image forming apparatus such as a copier 500 having a sound absorbing device using a Helmholtz resonator such as the sound absorbing device 600, an inner opening / closing cover such as a front opening / closing cover 101 that can be opened and closed with respect to the apparatus main body is opened. The sound absorbing device is provided on the inner surface such as the inner back surface 102r of the interior cover such as the inner cover 102 where the outer surface such as the surface 102f is exposed.
According to this, since the sound absorbing device is provided on the inner surface of the interior cover as described in the above embodiment, the sound absorbing device using the Helmholtz resonator is exposed even if the user opens the exterior opening / closing cover. Can be suppressed. In addition, since the sound absorbing device is provided not in the exterior opening / closing cover but in the interior cover, the exterior opening / closing cover does not become heavy due to the provision of the sound absorbing device, and the exterior opening / closing cover of the exterior opening / closing cover can be provided even in a configuration including the sound absorbing device. A decrease in operability can be suppressed. Furthermore, since the sound absorbing device is provided in the interior cover disposed inside the exterior opening / closing cover, it is possible to suppress leakage of sound from the surface on which the exterior opening / closing cover is provided.
As described above, according to the aspect A, it is possible to suppress the leakage of sound from the surface provided with the exterior opening / closing cover while suppressing the deterioration of the operability of the exterior opening / closing cover and the exposure of the communication portion of the Helmholtz resonator. it can.

(Aspect B)
In aspect A, the interior cover is provided with wall portions such as ribs 120 that protrude from the inner surface of the interior cover such as the inner cover 102 toward the inside of the apparatus and form the wall surface of the cavity of the Helmholtz resonator such as the cavity 601. A sound absorbing device is formed by mounting a cover member such as a sound absorbing cover member 620 that covers the front end side of the wall in the protruding direction.
According to this, as described in the above embodiment, the wall portion that forms the wall surface of the cavity of the sound absorbing device is formed integrally with the interior cover, so that the number of parts can be reduced, and the sound absorbing device An increase in the cost of the structure provided with the can be suppressed. In addition, when the frequency to be sound-absorbed is changed by using the lid as a separate member, the sound-absorbing device can be tuned only by slightly correcting the shape of the lid.

(Aspect C)
In any of the aspects A and B, the outer side of the wall part of the rib 120 or the like that forms the wall surface of the cavity of the Helmholtz resonator such as the cavity 601 in the space inside the interior cover such as the inner cover 102 An interior cover through-hole such as a through-hole 102c that penetrates the interior cover is provided so that the space such as the space T communicates with the space outside the interior cover.
According to this, since the interior cover through hole is provided in the interior cover at a position opposite to the space outside the portion forming the Helmholtz resonator, as described in the above embodiment, the interior cover through hole is provided. Even if it is a structure, the fall of the sound absorption effect can be prevented. Furthermore, by providing the interior cover through-hole, it is possible to access the inside of the interior cover, such as cleaning the glass member 47a of the laser writing device 47, without removing the interior cover.

(Aspect D)
In the aspect D, a sound absorbing device such as a plurality of sound absorbing devices 600 is provided on an inner surface such as the inner back surface 102r of the interior cover such as the inner cover 102, and the ribs 120 of two adjacent sound absorbing devices among the plurality of sound absorbing devices. Are arranged so as to have a gap such as a space T, and the interior cover through hole such as the through-hole 102c communicates the gap and the space outside the interior cover.
According to this, as described in the above embodiment, since the adjacent sound absorbing devices are installed with a space open, resonance between the sound absorbing devices can be prevented, and a decrease in the sound absorbing effect due to the resonance can be prevented. . In addition, by providing an interior cover through hole in the portion of the interior cover that is opposite to the space that has the effect of preventing resonance, space saving is achieved so that the inside of the interior cover can be accessed without removing the interior cover. be able to.

DESCRIPTION OF SYMBOLS 8 Photoconductor cleaning blade 9 Static elimination lamp 10 Photoconductor 11 Charging device 12 Developing device 13 Transfer unit 14 Cleaning device 15 First belt stretching roller 16 Second belt stretching roller 17 Transfer belt 18 Cleaning blade 20 Toner replenishing device 20a Bottle set Hole 21 Registration roller pair 22 Heat fixing device 30 Heating roller 32 Pressure roller 34 Discharge branch claw 35 Discharge roller 36 First pressure roller 37 Second pressure roller 38 Roller with stiffness 39 Discharge stack unit 42 Switchback device 43 Switchback Roller pair 44 Switchback position 47 Laser writing device 47a Glass member 48 Polygon mirror 49 Polygon motor 53 Light source 54 Mirror 55 Imaging optical lens 56 Image sensor 57 Contact glass 60 Paper transport device 61 Recording paper cassette 61a Recording paper cassette outer cover 62 Calling roller 63 Supply roller 64 Separation roller 66 Recording paper transport roller pair 67 Manual feed tray 68 Manual paper feed unit 100 Copier main body 101 Front opening / closing cover 102 Inner cover 102a Upper front Inner cover 102b Lower front inner cover 102c Through hole 102f Inner front surface 102r Inner back surface 103 Left side exterior cover 120 Rib 121 Developing roller 122 Lid unit 160 Sound absorbing device installation unit 200 Image reading device 300 Recording paper bank 400 Automatic document conveying device 470 Writing device holding frame 500 Copier 510 Front housing 510a Sound absorber installation opening 520 Left side housing 530 Rear housing 600 Sound absorber 601 Cavity 602 Opening 603 610 Sound absorbing body member 620 Sound absorbing cover member 630 Sound absorbing cap member 700 Glass cleaning member B Transfer position C Transfer belt cleaning unit P Recording paper R Recording paper transport path R1 Supply path R2 Manual feed path R3 Reversal path R4 Re-transport path S Opening Area T Space V Volume

JP 2000-235396 A JP 2000-112306 A

Claims (4)

In an image forming apparatus having a sound absorbing device using a Helmholtz resonator,
The sound-absorbing device to the inner surface of the interior cover the outer surface is exposed is provided by opening the openable outer cover relative to the apparatus main body,
An interior that penetrates the interior cover so as to communicate the space outside the wall portion forming the wall surface of the cavity of the Helmholtz resonator in the space inside the interior cover and the space outside the interior cover. An image forming apparatus having a cover through hole .   The image forming apparatus according to claim 1.
  A plurality of the sound absorbing devices are provided on the inner surface of the interior cover,
  The wall portions of two adjacent sound absorbing devices among the plurality of sound absorbing devices are arranged so as to have a gap, and the interior cover through-hole communicates the clearance with the space outside the interior cover. An image forming apparatus. The image forming apparatus according to claim 1 or 2 ,
Lid said projecting relative to the inner surface from the apparatus inside of the interior cover, the provided the wall portion forming a wall surface of the cavity of the Helmholtz resonator in the interior cover, it covers the distal end side of the protruding direction of the wall portion An image forming apparatus, wherein the sound absorbing device is formed by mounting a member .   In an image forming apparatus having a sound absorbing device using a Helmholtz resonator,
  The sound absorbing device is provided on the inner surface of the interior cover where the outer surface is exposed by opening an exterior opening / closing cover that can be freely opened and closed with respect to the device body,
  An image forming apparatus, wherein the sound absorbing device is removable from the interior cover.

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