JP6143200B2 - Image forming apparatus - Google Patents

Description

  The present invention relates to an image forming apparatus.

  2. Description of the Related Art Conventionally, an image forming apparatus that includes a sound absorbing device that uses a Helmholtz resonator to suppress leakage of driving sound to the outside is known.

  Patent Document 1 describes a configuration in which sound absorbing means using a Helmholtz resonator is arranged on a member that forms a recording medium conveyance path in the vicinity of a discharge port for discharging a recording medium such as transfer paper on which an image is formed by an image forming unit. Has been. With this configuration, the sound emitted from the discharge port to the outside of the image forming apparatus can be reduced.

However, in the image forming apparatus described in Patent Document 1, it is necessary to secure a space in which a resonance box of the Helmholtz resonator is provided around the recording medium conveyance path in the vicinity of the discharge port, and the recording medium conveyance reaching the discharge port in the apparatus. The part which forms a path will enlarge.
Such a problem is not limited to the sound absorbing means for attenuating the sound, but may occur if the sound absorbing means is provided in the recording medium conveyance path near the discharge port.

In order to solve the above-described problems, the invention according to claim 1 is an image forming apparatus that includes an image forming unit that forms an image on a recording medium and discharges the image from a discharge port, and a sound absorbing unit. And a discharge recording medium storage portion that stores the recording medium discharged from the discharge port, and the sound absorbing means is provided in the discharge recording medium storage portion . The sound absorbing means uses a Helmholtz resonator, and the neck of the Helmholtz resonator is formed by a burring part obtained by burring a sheet metal, and the burring part accommodates the discharged recording medium with respect to the sheet metal. It is a shape which protrudes on the opposite side to a part .

  According to the present invention, it is possible to prevent the sound generated inside the apparatus from being transmitted to the outside from the discharge port to become noise, and to suppress the increase in the size of the portion that forms the recording medium conveyance path to the discharge port in the device. There is an excellent effect that it is possible to do.

FIG. 4 is an explanatory view of a characteristic part of the copying machine according to the present embodiment, (a) is an explanatory perspective view of the copying machine, and (b) is an explanatory perspective view of the sound absorbing device when the lower surface of the scanner is viewed from below. 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. The schematic diagram of the sound-absorbing device using a Helmholtz resonator. Sectional drawing of the sound-absorbing device which concerns on this embodiment. Explanatory drawing which looked at the in-body discharge part from the top. Sectional drawing of the sound-absorbing device which concerns on a modification.

  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, a scanner 200 as an image reading unit is attached on the image forming unit 100 of the copier 500, and the image forming unit 100 is placed on a recording paper bank 300. Mounted on the scanner 200 is an automatic document feeder 400 configured to be rotatable about the back side (the back side in the drawing).

  As shown in FIG. 2, a sound absorbing device 600 is arranged inside the scanner 200. In the copying machine 500, the neck portion of the Helmholtz silencer is formed by burring the sheet metal forming the scanner 200. The neck forms a Helmholtz silencer hole 630.

  Inside the image forming unit 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. The transfer belt 17 is pressed against the circumferential surface of the photoconductor 10 at a transfer position B where the toner image on the photoconductor 10 is transferred to a recording paper P that is a recording medium.

  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, it is scraped off by the belt cleaning blade 18 that has come into contact.

  Further, the image forming unit 100 is provided with a toner replenishing device 20 that replenishes 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 image forming unit 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 unit 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 image-formed recording paper P that has passed through the thermal fixing device 22 is also provided.

  Further, the image forming unit 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 image forming unit 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, a polygon mirror 48 which is a rotating polygon mirror for scanning, a polygon motor 49, and an fθ lens.

The scanner 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, and a document stacking table is provided at a document discharge position. The automatic document conveying device 400 includes a plurality of document conveying rollers. The document conveying rollers convey the document from the document setting table to the document stacking table through the reading position on the contact glass 57 of the scanner 200.

  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 figure, the above-described supply path R1 leading to the recording paper conveyance path R of the image forming unit 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 image forming unit 100 is provided with a manual paper feeding 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 making a copy using the copying machine 500, first, the main switch is turned on and a document is set on the 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 scanner 200, and the automatic document feeder 400 is closed and pressed.

Thereafter, when the start switch is pressed, when a document is set on the automatic document feeder 400, the scanner 200 is driven after the document is moved onto the contact glass 57 through the document conveyance path by the document conveyance roller. Then, the document content is read and discharged onto the document stacking table. On the other hand, when an original is directly set on the contact glass 57, the scanner 200 is immediately driven to read the original content.
When reading the document content, the scanner 200 irradiates the document 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 the photosensitive member driving motor simultaneously with reading of 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 scanner 200 to form an electrostatic latent image on the surface of the photosensitive member 10. The surface potential of the portion (latent image portion) irradiated with the laser light 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 using the manual paper feed unit 68, the manual feed tray 67 is opened and the recording paper P is set thereon. Also in this case, the recording paper P set on the manual feed tray 67 is transported to the manual feed path R2 by the calling roller 62, the supply roller 63 and the separation roller 64, and the recording paper transport roller pair 66 transports the recording paper. You are led to Road R. The recording paper P guided to the recording paper conveyance path R abuts against the registration roller pair 21 and is stopped.
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 at the transfer position B 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, and is discharged from the discharge port 40 onto the discharge stack portion 39, Stacked there.

  When images are 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 transferred from the recording paper conveyance path R to the reverse path. Put in 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 copying machine 500 of this embodiment will be described.
FIG. 1 is an explanatory diagram of a characteristic part of the copying machine 500. FIG. 1A is a perspective explanatory view of the copying machine 500, and FIG. 1B is a sound absorption when the scanner lower surface 203 which is the lower surface of the scanner 200 of the copying machine 500 shown in FIG. FIG.

As shown in FIGS. 1A and 2, the copying machine 500 has a recording medium on which an image is formed by the image forming unit 100 disposed above the in-body sheet discharge unit 41 that is discharged from a sheet discharge port 40 that is a discharge port. This is an in-body discharge type image forming apparatus in which a scanner 200 is disposed and an image forming unit 100 is disposed below. The recording sheet P on which an image has been formed is discharged from the discharge port 40 to the in-body discharge unit 41 and stacked on the discharge stack unit 39.
Further, as shown in FIG. 1, a sound absorbing device 600 that is a sound absorbing means is provided on the scanner lower surface 203 forming the in-body discharge section 41.

The sound absorbing device 600 provided in the copying machine 500 of this embodiment is a sound absorbing device using a Helmholtz resonator.
FIG. 4 is a schematic diagram of a sound absorbing device 600 using a Helmholtz resonator.
As shown in FIG. 4, the Helmholtz resonator is shaped like a container with a narrow inlet, 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：開口端補正）

(Δr: Open end correction)

“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.

Inside the image forming unit 100, various sounds such as driving sound of a driving motor that transmits rotational driving to various rollers, moving sound of moving members such as various rollers, and rotating sound of the polygon mirror 48 of the laser writing device 47, etc. Will occur. Such a sound may be transmitted to the outside of the copier 500, resulting in noise that causes discomfort to surrounding people. Sound generated inside the image forming unit 100 is suppressed from being transmitted to the outside by a member that shields the inside and outside of the copying machine 500 such as an exterior cover.
However, since the discharge port 40 is inevitably an opening of the image forming unit 100 and there is no obstruction, the sound generated inside the image forming unit 100 leaks out of the discharge port 40, and noise is generated. It becomes a factor that occurs.

  To solve such a problem, it is conceivable to arrange a sound absorbing device using a Helmholtz resonator in the recording paper conveyance path R in the vicinity of the paper discharge port 40. However, since the image forming apparatus is a precision machine having a large number of parts, the contents are large, and there is little space in which the Helmholtz resonator can be arranged in the recording paper conveyance path R in the vicinity of the paper discharge port 40. In addition, even if space can be secured, it cannot be placed in an effective position to suppress the transmission of sound to the user's position, the number of places that can be placed is small, and the sound absorption effect cannot be enhanced so much There is.

  In contrast, the copying machine 500 according to the present embodiment is provided with the sound absorbing device 600 on the scanner lower surface 203 that forms the in-cylinder paper discharge unit 41, so that sound leaked from the paper discharge port 40 to the in-cylinder paper discharge unit 41. Can be absorbed before the user senses it, and noise can be suppressed.

As shown in FIG. 1, a hole 630 is provided in a scanner lower frame 604 that is a structure that forms a scanner lower surface 203 serving as a ceiling surface of the in-body discharge unit 41. The hole portion 630 corresponds to the communication portion 603 described with reference to FIG.
FIG. 5 is a cross-sectional view of the sound absorbing device 600 according to the present embodiment. As shown in FIG. 5, resonance is performed by forming a hole 630 by performing a burring process on a scanner lower frame 604 made of sheet metal, and forming a cavity 601 on the upper surface of the scanner lower frame 604 at the position where the hole 630 is provided. A box 608 is arranged. The resonance box 608 is fixed to the scanner lower frame 604 by a fastening screw 640 to form a sound absorbing device 600 that is a Helmholtz resonator. The fixing of the resonance box 608 to the scanner lower frame 604 is not limited to a screw, and other fixing means such as a double-sided tape or a sealant may be used.

  By forming a hole 630 in a scanner lower frame 604 that is a framework member of the scanner 200 and attaching a resonance box 608 to form a Helmholtz resonator, the number of parts can be reduced and space can be saved.

  As shown in FIGS. 1B and 5, the copying machine 500 is provided with a recessed portion 607 in the scanner lower frame 604. As a result, the sound transmitted toward the lower surface of the scanner lower frame 604 bounces off at the dent-shaped portion 607 and becomes easy to enter the hole 630 of the sound absorbing device 600. Further, by providing the recessed shape portion 607, the scanner lower frame 604 is not a mere flat plate, but is formed into a three-dimensional shape by bending or flattening a flat metal plate. As described above, since the three-dimensional shape increases the strength of the lower scanner frame 604 and makes it difficult to deform, the hermeticity between the lower scanner frame 604 and the resonance box 608 is difficult to drop.

  Further, the recessed shape portion 607 has a shape recessed toward the side farther from the in-body discharge portion 41 than the peripheral portion of the scanner lower frame 604. Thereby, protruding parts such as screws can be prevented from interfering with the user. Further, the strength is increased by the dimples and the bent shape for the depression, and the sealing property between the scanner lower frame 604 and the resonance box 608 is easily maintained. Furthermore, a wall is formed around the sound absorbing device 600, so that sound is easily collected in the hole portion 630 of the sound absorbing device 600, and sound is likely to enter the hole portion 630, so that the sound absorbing effect can be improved.

  The hole 630 may be a simple hole obtained by punching the plate-like scanner lower frame 604, but when the scanner lower frame 604 is a sheet metal, the length “H” of the communication portion 603 can be earned by burring. In this case, as shown in FIG. 5, the shape protruding by the burring process is directed to the upper surface side of the scanner lower frame 604, that is, the inside of the scanner 200, whereby the edge of the sheet metal by the burring process becomes invisible and the safety is improved.

FIG. 6 is an explanatory view of the in-body discharge unit 41 as viewed from above.
The arrow α in FIG. 6 is the paper discharge direction, the arrow β in FIG. 6 indicates the front side of the copier 500, and the direction indicated by the arrow β is the front side of the paper in FIG. In the copying machine 500 of this embodiment, a sound absorbing device 600 is provided in a scanner lower frame 604 located above a region on the front side of the in-body discharge unit 41 indicated by “γ” in FIG.

  It is assumed that the user stands on the front side of the copier 500 in order to operate the operation panel 501 and collect the output recording paper P. Among the sounds emitted from the paper discharge port 40, most of the sound transmitted to the in-body paper discharge unit 41 and transmitted to the position of the user standing on the front side of the copier 500 is indicated by γ in FIG. Go through the area. As described above, by arranging the sound absorbing device 600 above the region γ through which the sound toward the user passes, it is possible to effectively suppress the sound output from the paper discharge port 40 from being transmitted to the user's position. Can do. Thus, by providing the sound absorbing device 600 around the in-body paper discharge unit 41, which is one of the locations that the user is closest to, unpleasant noise for the user can be effectively suppressed.

  In the scanner 200 of the present embodiment, a scanner driving mechanism that moves the light source 53 and the plurality of mirrors 54 in the housing in the sub-scanning direction (left-right direction in FIG. 2) is arranged on the back side of the apparatus. . The scanner driving mechanism has a height higher than the area where the light source 53 and the mirror 54 move, and the height of the scanner 200 is adjusted to the height of the scanner driving mechanism, so the mirror 54 in the housing of the scanner 200 moves. There is a spatial margin below the area. By disposing the sound absorbing device 600 in the space portion, the enlargement of the copying machine 500 is suppressed while suppressing the sound generated inside the device from being transmitted to the outside through the discharge port and becoming noise. It becomes possible.

  The sound leaking from the paper discharge port 40 is mainly a paper sliding sound, but also includes operating sounds of various members in the image forming unit 100. Therefore, it is not a specific peak sound but a sound having a different frequency. Leaks out. For this reason, since it is difficult to arrange the sound absorbing device 600 corresponding to all frequencies, it corresponds to a frequency that is easily worried about human hearing, for example, a frequency of 1000 [Hz] to 1500 [Hz]. The sound absorbing device 600 is disposed. Thereby, it can suppress efficiently that the sound which leaked from the paper discharge outlet 40 turns into a noise. In addition, since the sound absorbing device 600 has the hole 630 opened toward the in-cylinder paper discharge unit 41, the sound that has reached the in-cylinder paper discharge unit 41 can easily enter the hole 630 and efficiently absorb sound. it can.

  In the copier 500 of this embodiment, as shown in FIG. 6, the sound absorbing device 600 is arranged only on the front side of the scanner lower surface 203. The arrangement of the sound absorbing device 600 is not limited to this, and the sound absorbing device 600 may be provided in the entire area of the scanner lower surface 203 as long as there is room in the space inside the housing of the scanner 200. In addition, the scanner 200 has a larger space in the housing than other structures, and a large number of sound absorbing devices 600 including Helmholtz resonators can be arranged. By providing a large number of sound absorbing devices 600, Helmholtz resonators corresponding to different frequencies can be formed, and the sound absorbing effect can be improved.

The position where the sound absorbing device 600 is provided is not limited to the lower surface 203 of the scanner, and the sound transmitted to the outside from the paper discharge port 40 by being provided on the surface on which the in-body paper discharge unit 41 such as the scanner support side plate 410 is formed. Can be prevented from becoming noise.
In the recording paper conveyance path R in the vicinity of the paper discharge port 40, a plurality of conveyance rollers and a roller driving mechanism for driving them are arranged, so that there is no space for arranging the sound absorbing device 600. When the sound absorbing device 600 is arranged in such a recording paper conveyance path R, the space for arranging the conveyance mechanism increases, leading to an increase in the size of the copying machine 500 as a whole. In addition, even if a space for arranging the sound absorbing device 600 can be secured, there are problems that the sound absorbing device 600 cannot be arranged at an effective position, the number that can be arranged is small, and the sound absorbing effect cannot be enhanced so much.

  On the other hand, in the copying machine 500 of this embodiment, the sound absorbing device 600 is provided in the scanner 200 that is a structure that forms the in-body discharge unit 41. The size of the structure forming the in-body discharge unit 41 is determined by the maximum contents in each direction in the front-rear direction, the left-right direction, and the height direction of the casing. Further, since there are not many members to be arranged as in the vicinity of the recording paper conveyance path R, a spatial margin is likely to be generated inside the housing. By disposing the sound absorbing device 600 in such a space-allowing portion, it is possible to suppress the sound transmitted to the outside from the paper discharge port 40 from becoming noise.

  Further, in the copying machine 500, the sound absorbing device 600 is provided on the scanner lower surface 203 of the scanner 200 positioned above the in-body discharge unit 41. When the sound absorbing device 600 is provided in the discharge stack portion 39 located below the in-body discharge portion 41, the recording paper P separates the sound absorbing device 600 and the discharge port 40 when the recording paper P is stacked. Therefore, the sound absorption effect is reduced. On the other hand, by arranging the sound absorbing device 600 above the in-body discharge unit 41, even if the recording paper P is stacked, the recording paper P separates the discharge port 40 and the sound absorbing device 600 from each other. The sound absorbing effect can be maintained.

[Modification]
FIG. 7 is a cross-sectional view of a sound absorbing device 600 provided in a copying machine 500 according to a modification including the features of the present invention. Since the sound absorbing device 600 is common to the copier 500 of the above-described embodiment except that some positions of the plurality of holes 630 provided in the sound absorbing device 600 are different, the description of the common configuration is omitted and the differences are described. To do.

As shown in FIG. 7, in the sound absorbing device 600 of the modification, a hole 630 that communicates a part of the plurality of cavities 601 with the outside is provided in the scanner lower frame 604, and other cavities are provided. A hole 630 of the part 601 is provided on the side wall of the resonance box 608.
In the modified example, the sound absorption frequency of the Helmholtz resonator formed by the cavity 601 in which the hole 630 is provided in the scanner lower frame 604 is set to the frequency of the sound leaking from the paper discharge port 40. On the other hand, the sound absorption frequency of the Helmholtz resonator formed by the cavity 601 in which the hole 630 is provided in the side wall of the resonance box 608 is matched with the frequency of the sound generated inside the scanner 200. Thereby, in the configuration of the modified example, not only the sound leaking from the paper discharge port 40 is suppressed by one sound absorbing device 600, but also the sound generated inside the scanner 200 is noise. It becomes possible to suppress.

  In the above-described embodiments and modifications, the copying machine 500 which is an electrophotographic image forming apparatus has been described. However, the image forming apparatus is not limited to the electrophotographic system. The present invention is applicable to any in-body discharge type image forming apparatus that discharges a recording medium on which an image has been formed from a discharge port.

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)
A copying machine 500 having an image forming unit such as the image forming unit 100 that forms an image on a recording medium such as the recording paper P and discharges it from a discharge port such as a paper discharge port 40, and a sound absorbing means such as a sound absorbing device 600; In the image forming apparatus, the recording is a space that is open on at least one side of the apparatus main body such as the front surface of the apparatus and is exposed to the discharge port, and is discharged from the in-body discharge unit 41 that accommodates the recording medium discharged from the discharge port. A medium accommodating portion is provided, and a sound absorbing means is provided in the discharged recording medium accommodating portion such as the scanner lower surface 203.
According to this, as described in the above embodiment, the sound coming out from the discharge port is transmitted into the discharge recording medium storage unit, but by providing the sound absorption means in the discharge recording medium storage unit, the discharge recording medium storage It can suppress that the sound which came out to the part is transmitted to the circumference | surroundings of an apparatus from opening. Thereby, it can suppress that the sound which generate | occur | produced inside the apparatus is transmitted outside from a discharge port, and becomes noise. In addition, it is not necessary to secure a space for providing sound absorbing means in the vicinity of the recording medium conveyance path in the vicinity of the discharge port, and therefore it is possible to suppress an increase in the size of the part that forms the recording medium conveyance path to the discharge port in the apparatus. It becomes. As described above, in the aspect A, it is possible to increase the size of the part that forms the recording medium conveyance path to the discharge port in the device while suppressing the sound generated inside the device from being transmitted to the outside through the discharge port. It becomes possible to suppress.

(Aspect B)
In the aspect A, the sound absorbing means such as the sound absorbing device 600 is provided on the lower surface of the member such as the scanner 200 positioned above the discharged recording medium accommodating portion such as the in-body discharging portion 41.
According to this, as described in the above embodiment, even when a recording medium such as the recording paper P is stacked in the discharged recording medium accommodating portion, the recording medium is located between the discharge port such as the discharge port 40 and the sound absorbing means. The sound absorption effect can be maintained without separating them.

(Aspect C)
In either aspect A or B, sound absorbing means such as the sound absorbing device 600 is disposed between a predetermined position operated by the user, such as a position on the front side of the apparatus, and a discharge port such as the discharge port 40.
According to this, as described in the above-described embodiment, the sound absorbing means is disposed between the position that is considered to be operated by the user, such as the vicinity of the operation panel 501, and the discharge port, thereby coming out of the discharge port. It is possible to effectively suppress the transmission of sound to the user's position. Thereby, it can suppress effectively that the operation sound which may give an unpleasant feeling to a user transmits to a user, and becomes a noise.

(Aspect D)
In any of the aspects A to C, the sound absorbing means such as the sound absorbing device 600 uses a Helmholtz resonator.
According to this, as described in the above embodiment, by adjusting the sound absorption frequency of the Helmholtz resonator to the frequency of the sound to be absorbed, the sound transmitted to the discharged recording medium accommodating portion such as the in-body discharge portion 41 is absorbed. It is possible to realize sound absorbing means.
In addition, as a sound absorbing means other than the configuration using the Helmholtz resonator, a configuration using a sound absorbing material such as sponge or glass wool can be cited.

(Aspect E)
In the aspect D, a metal skeleton member of the apparatus main body such as the scanner lower frame 604 is used as a member for forming a neck portion of the communication portion 603 of the Helmholtz resonator.
According to this, as described in the above embodiment, by reducing the number of parts by forming holes such as the holes 630 in the framework member and attaching a container member such as the resonance box 608 to form a Helmholtz resonator, And space saving can be achieved.

(Aspect F)
In claim E, the portion where the Helmholtz resonator is provided in the frame member such as the scanner lower frame 604 has a shape with a step from the periphery.
According to this, as described in the above embodiment, since the three-dimensional shape increases the strength of the skeleton member and makes it difficult to deform, the sealing performance between the skeleton member and the container member such as the resonance box 608 is improved. It becomes easy to secure.

(Aspect G)
In the aspect F, the portion forming the Helmholtz resonator is recessed from the peripheral portion with respect to the discharge recording medium accommodating portion such as the in-body discharge portion 41.
According to this, as described in the above embodiment, it is easy for sound to collect at the entrance of the neck portion of the communicating portion 603 of the sound absorbing means such as the sound absorbing device 600, and it is easy for sound to enter the neck portion, so that the sound absorbing effect is obtained. Improvements can be made.

(Aspect H)
In any one of the aspects D to G, a neck part of the communication part 603 of the Helmholtz resonator is formed by a burring part obtained by burring the sheet metal, and the burring part is an in-body discharge part 41 with respect to the sheet metal. The shape protrudes to the opposite side to the discharged recording medium accommodating portion.
According to this, as described in the above embodiment, the edge of the sheet metal by the burring process cannot be seen, the safety is improved, and the burring portion can be prevented from getting in the way of the user.

(Aspect I)
In any one of claims D to H, a plurality of Helmholtz resonators are provided, and at least one Helmholtz resonator has a resonance frequency different from that of other Helmholtz resonators.
According to this, as described in the above embodiment, Helmholtz resonators corresponding to different frequencies can be formed, and the sound absorption effect can be improved.

(Aspect J)
In any one of the aspects D to I, an image reading unit such as the scanner 200 as a structure forming the apparatus is provided above the discharge recording medium accommodating unit such as the in-body discharge unit 41, and the scanner of the image reading unit A container member such as a resonance box 608 that forms a resonance space is attached to a frame member such as the lower frame 604 to form a Helmholtz resonator.
According to this, as described in the above embodiment, the inside of the skeleton member of the image reading unit has a spatial margin and there are many open spaces, so that new parts can be easily attached. For this reason, when the container member can be put inside the framework member, or when the container member is attached from the outside of the framework member, the degree of freedom of the fastening portion of the fastening member such as the fastening screw 640 is high, Furthermore, the degree of freedom of arrangement of the Helmholtz resonator is high.

(Aspect K)
In the aspect J, the container member such as the resonance box 608 is disposed on the opposite side of the discharge recording medium accommodation portion such as the in-body discharge portion 41 with the framework member such as the scanner lower frame 604 interposed therebetween.
According to this, as described in the above embodiment, the hole shape of the Helmholtz resonator is provided in the skeleton member, and the container member is arranged on the upper portion of the skeleton member. The member forming the sound absorbing means does not protrude. Thereby, it is possible to prevent the newly provided sound absorbing means from interfering with the user.

  The present invention is not limited to the image forming apparatus in which the image forming unit and the image reading unit are provided above and below the in-body discharge unit. That is, the recording medium is discharged into a discharge recording medium accommodating portion provided in a space formed in the middle of the apparatus in the vertical direction of the apparatus, and a hand is inserted from the opening formed on the side surface of the apparatus main body. It may be configured to be put in and taken out.

  For example, a printer in which a discharge recording medium accommodating unit is provided in a space formed between an image forming unit provided in the upper part of the apparatus and a paper cassette provided in the lower part of the apparatus and opened in at least one side wall of the apparatus main body. It can also be applied to.

In addition, the discharge recording medium accommodating portion is not limited to the case where the discharged recording medium accommodating portion is provided in the space surrounded by the upper and lower walls and opened on the side surface of the apparatus main body, and the discharged recording medium accommodating portion is not surrounded by the upper wall or the lower wall. Alternatively, the recording medium may be discharged.
In other words, the present invention can also be applied to a printer or the like that has a discharge recording medium accommodating portion that is open at least on one side wall and is not surrounded by the upper wall.

  Further, the present invention can be applied to a printer, a copying machine, or the like that has a discharge recording medium accommodating portion that is open at least on one side wall and is not surrounded by a lower wall. For example, a recording medium is discharged from a discharge port to a discharge recording medium storage portion formed at a lower portion of the apparatus having an upper wall that surrounds the discharge recording medium storage section between the installation surface such as a floor or a stand on which the apparatus is installed. The present invention can also be applied to a printer or the like.

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 Belt cleaning blade 20 Toner replenishing device 21 Resist 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 39 Discharge stack part 40 Paper discharge port 41 In-body paper discharge part 42 Switchback Device 43 Switchback Roller Pair 44 Switchback Position 47 Laser Writing Device 48 Polygon Mirror 49 Polygon Motor 53 Light Source 54 Mirror 55 Imaging Optical Lens 56 Image Sensor 57 Contact Glass 60 Recording Paper Transport Device 61 Recording paper cassette 62 Call roller 63 Supply roller 64 Separation roller 66 Recording paper transport roller pair 67 Manual feed tray 68 Manual paper feed unit 100 Image forming unit 121 Developing roller 200 Scanner 203 Scanner lower surface 300 Recording paper bank 400 Automatic document transport device 410 Scanner support side plate 500 Copier 501 Operation panel 600 Sound absorbing device 601 Cavity 602 Opening 603 Communication 604 Scanner lower frame 607 Recessed part 608 Resonance box 630 Hole 640 Fastening screw B Transfer position C Transfer belt cleaning part P Recording paper R Recording paper transport path R1 Supply path R2 Manual feed path R3 Inversion path R4 Re-transport path

JP 2008-49587 A

Claims (9)

An image forming unit that forms an image on a recording medium and discharges the image from a discharge port;
In an image forming apparatus having sound absorbing means,
An opening at least on one side surface of the apparatus main body, and a space where the discharge port faces, and a discharge recording medium storage unit for storing a recording medium discharged from the discharge port;
In the configuration in which the sound absorbing means is provided in the discharged recording medium accommodating portion,
The sound absorbing means uses a Helmholtz resonator,
The neck portion of the Helmholtz resonator is formed by a burring portion obtained by performing burring processing on a sheet metal, and the burring portion has a shape protruding to the opposite side of the discharge recording medium accommodating portion with respect to the sheet metal. Image forming apparatus. An image forming unit that forms an image on a recording medium and discharges the image from a discharge port;
In an image forming apparatus having sound absorbing means,
An opening at least on one side surface of the apparatus main body, and a space where the discharge port faces, and a discharge recording medium storage unit for storing a recording medium discharged from the discharge port;
The sound absorbing means is arranged on the side of the apparatus main body provided with the operation part rather than the horizontal central part in the discharged recording medium accommodating part ,
All SANYO that said sound-absorbing means using Helmholtz resonator,
The neck portion of the Helmholtz resonator is formed by a burring portion obtained by performing burring processing on a sheet metal, and the burring portion has a shape protruding to the opposite side of the discharge recording medium accommodating portion with respect to the sheet metal. Image forming apparatus. The image forming apparatus according to claim 1 or 2,
An image forming apparatus using a metal frame member of the apparatus main body as a member forming a neck portion of the Helmholtz resonator. The image forming apparatus according to claim 3 .
The image forming apparatus according to claim 1, wherein a portion where the Helmholtz resonator is provided in the frame member has a stepped shape from the periphery. The image forming apparatus according to claim 4 .
An image forming apparatus having a shape in which a portion where the Helmholtz resonator is formed is recessed from a peripheral portion with respect to the discharged recording medium accommodating portion. The image forming apparatus according to claim 1乃 Itaru 5,
An image forming apparatus comprising a plurality of the Helmholtz resonators, wherein at least one of the Helmholtz resonators has a resonance frequency different from that of the other Helmholtz resonators. The image forming apparatus according to claim 1乃 Itaru 6,
An image reading unit as a structure forming an apparatus above the discharged recording medium housing unit;
An image forming apparatus, wherein a container member that forms a resonance space is attached to a frame member of the image reading unit to form the Helmholtz resonator. The image forming apparatus according to claim 7 .
An image forming apparatus, wherein the container member is disposed on the opposite side of the discharged recording medium accommodating portion with the skeleton member interposed therebetween. The image forming apparatus according to any one of claims 1 to 8,
An image forming apparatus, wherein the sound absorbing means is provided on a lower surface of a member positioned above the discharged recording medium accommodating portion.

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