JP2023018698A - image forming device - Google Patents

Abstract

To provide an image forming apparatus that has increased quietness.SOLUTION: A printer 100 comprises: an apparatus body 101; and a cassette 200 that has a sheet P loaded thereon and can be withdrawn from and attached to the apparatus body 101. The apparatus body 101 has a feeding roller 102 that feeds the sheet P loaded on the cassette 200, an image forming unit 120 that forms an image on the sheet P fed by the feeding roller 102, a driving source 140 that is arranged to overlap a sheet loading area R1 of the cassette 200 in plan view, a front face part 111 that constitutes part of an exterior 150 and is arranged on the opposite side of the image forming unit 120 across the driving source 140 in an X-direction, and a wall part 171 that is arranged between the driving source 140 and the front face part 111 in the X-direction. A space S1 is defined between the front face part 111 and the wall part 171.SELECTED DRAWING: Figure 1

Description

The present invention relates to an image forming apparatus having an image forming section that forms an image on a sheet.

An image forming apparatus includes an image forming section that forms an image on a sheet, and a drive source that operates when the image forming section forms an image on the sheet. When the drive source operates, the drive source generates operating noise. Therefore, the drive source is generally provided inside the exterior of the image forming apparatus. Also, as an exterior of an image forming apparatus, as described in Japanese Patent Application Laid-Open No. 2002-200300, an exterior having an enhanced soundproofing effect by a sound absorbing member is known.

Japanese Patent Application Laid-Open No. 2007-316351

However, even if the drive source is arranged inside the exterior, it may not be possible to completely prevent the operating sound of the drive source from leaking to the exterior of the exterior.

An object of the present invention is to provide an image forming apparatus with improved quietness.

An image forming apparatus according to the present invention includes an apparatus main body and a sheet stacking section on which sheets are stacked and which can be pulled out and attached to the apparatus main body, and the apparatus main body is stacked on the sheet stacking section. a feeding rotator for feeding a sheet, an image forming section for forming an image on the sheet fed by the feeding rotator, and the sheet stacking section in a state in which the sheet stacking section is attached to the apparatus main body. a driving source disposed so as to overlap with a sheet stacking area in which sheets of the maximum usable size can be stacked in a plan view; and a first wall portion disposed on the side opposite to the image forming section with the drive source interposed therebetween in an orthogonal direction orthogonal to the direction of , and the drive source and the first wall portion in the orthogonal direction. and a second wall disposed therebetween, wherein a space is defined between the first wall and the second wall.

According to the present invention, quietness can be enhanced.

1 is a schematic diagram showing a longitudinal section of a printer as an example of an image forming apparatus according to a first embodiment; FIG. 1 is a perspective view of a printer according to a first embodiment; FIG. 1 is a perspective view of a printer in which the interior of the printer according to the first embodiment is seen through; FIG. 1 is a perspective view of a printer in which the interior of the printer according to the first embodiment is seen through; FIG. FIG. 10 is a schematic diagram showing a longitudinal section of a printer as an example of an image forming apparatus according to a second embodiment; FIG. 11 is a perspective view of the printer in which the inside of the printer according to the second embodiment is seen through; 5 is a schematic diagram showing a longitudinal section of a printer of Comparative Example 1; FIG.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments for carrying out the present invention will be described in detail with reference to the drawings.

<First Embodiment>
FIG. 1 is a schematic diagram showing a longitudinal section of a printer 100, which is an example of an image forming apparatus according to the first embodiment. FIG. 2 is a perspective view of the printer 100 according to the first embodiment. The printer 100 is an electrophotographic laser beam printer that forms a monochrome toner image. The printer 100 includes an apparatus main body 101 and a cassette 200 that is an example of a sheet stacking unit that can be pulled out from and attached to the apparatus main body 101 . Sheets P are stacked on the cassette 200 . The sheet P includes recording media such as paper such as plain paper and envelopes, plastic film (OHT) for overhead projectors, and cloth.

The apparatus main body 101 includes a feeding roller 102, which is an example of a feeding rotary member that feeds the sheets P stacked in the cassette 200, and a sheet conveying unit 103 that conveys the sheet P fed by the feeding roller 102. , has The apparatus main body 101 also has an image forming unit 120 that forms an image on the sheet P fed by the feeding roller 102 and conveyed by the sheet conveying unit 103 . Further, the apparatus main body 101 has a fixing device 6 that fixes the image transferred to the sheet P, and a pair of discharge rollers 106 that can discharge the sheet P to the discharge tray 107 .

The cassette 200 has a cassette body 201 as a sheet stacking unit body, a middle plate 202 supported by the cassette body 201 so as to be able to move up and down, and a spring member 203 that presses the middle plate 202 upward. As the intermediate plate 202 is pushed up by the spring member 203 , the downstream end of the sheet P stacked on the intermediate plate 202 is pressed against the feeding roller 102 .

When an image forming command is output to the printer 100 , the image forming process by the image forming section 120 is started based on image information input from an external computer or the like connected to the printer 100 . The image forming section 120 has a process cartridge 130 and a transfer roller 5 . The process cartridge 130 includes a photosensitive drum 1 , which is an example of an image carrier, a charging roller 2 , a developing device 4 including a developing roller 41 , and a cleaning device 7 including a cleaning blade 71 . The charging roller 2 , developing roller 41 and cleaning blade 71 are arranged along the outer periphery of the photosensitive drum 1 . The photosensitive drum 1 and the transfer roller 5 form a transfer nip T. As shown in FIG. The process cartridge 130 is detachable from the apparatus main body 101 .

Further, the device body 101 has a drive source 140 . The drive source 140 operates when the image forming section 120 forms an image on the sheet P. FIG. In the first embodiment, drive source 140 includes motor 50 and laser scanner 3 . Motor 50 is, for example, a brush motor. The motor 50 rotates the photosensitive drum 1 in the direction of arrow R at a predetermined process speed, ie, a predetermined peripheral speed, via a gear (not shown). In the first embodiment, the subject to be driven by the motor 50 is the photosensitive drum 1, but the subject is not limited to this. For example, in addition to the photosensitive drum 1 or instead of the photosensitive drum 1 , a rotating body other than the photosensitive drum 1 may be rotated by the motor 50 .

The photosensitive drum 1 includes a cylindrical drum base and a photosensitive material provided on the drum base. The drum substrate is made of, for example, an aluminum alloy or nickel. The photosensitive material is, for example, OPC (organic photo-semiconductor), amorphous selenium, amorphous silicon, or the like. The surface of the photosensitive drum 1 is uniformly charged to a predetermined polarity and potential by the charging roller 2 .

The laser scanner 3 scans and exposes the photosensitive drum 1 in the longitudinal direction with a laser beam E that is ON/OFF controlled in accordance with input image information. As a result, the charge on the exposed portion of the surface of the photosensitive drum 1 is removed and an electrostatic latent image is formed. After that, toner is attached to the electrostatic latent image by the developing roller 41 to develop a monochrome toner image on the photosensitive drum 1 . Developing methods include a jumping developing method, a two-component developing method, a contact developing method, and the like, and are used in combination with image exposure and reversal development. In this embodiment, a jumping development method is used.

Sheets P stacked in the cassette 200 are fed by the feeding roller 102 in parallel with the image forming process. The sheet conveying unit 103 has a conveying roller 21 and a driven roller 23 that rotates following the conveying roller 21 . The conveying roller 21 and the driven roller 23 convey the sheet P from below to above. The fed sheet P is conveyed toward the transfer nip T by the conveying nip N formed by the conveying roller 21 and the driven roller 23 . The conveying roller 21 and the driven roller 23 may constitute a registration roller pair that corrects the skew of the sheet P by abutting the leading edge of the sheet P against the conveying nip N.

The downstream end of the sheet P conveyed by the conveying nip N is detected by the top sensor 104 . Then, based on the position of the top sensor 104, the position of the transfer nip T, and the conveying speed of the sheet P, the timing at which the downstream end of the sheet P reaches the transfer nip T is obtained. After that, the toner image on the photosensitive drum 1 is transferred at the transfer nip T to the sheet P conveyed by the transfer nip N due to the electrostatic load bias applied to the transfer roller 5 . Residual toner remaining on the photosensitive drum 1 is collected by the cleaning blade 71 . The fixing device 6 applies predetermined heat and pressure to the sheet P onto which the toner image has been transferred, thereby melting and fixing (fixing) the toner.

The fixing device 6 has a fixing film 10 containing a heater (not shown) and a pressure roller 20 that presses against the fixing film 10 . After passing through the fixing device 6 , the sheet P is discharged onto the discharge tray 107 by the discharge roller pair 106 . During this time, the timing at which the downstream end and the upstream end of the sheet P pass the discharge sensor 105 is detected, and it is determined whether or not the sheet P has jammed or the like.

Although the printer 100 of the first embodiment is configured to be capable of single-sided printing only, a duplex conveying path is provided downstream of the fixing device 6 in the sheet conveying direction, and the sheet P having an image formed on the first surface can be printed on both sides. It may be constructed so as to be guided to the transfer nip T again by the transport path. Further, although the fixing device 6 has the fixing film 10, the fixing device 6 is not limited to this, and the fixing device may have a fixing roller and a heating roller.

Here, the direction of the rotation axis L1 of the feed roller 102 is the Y direction, the vertical direction perpendicular to the installation surface on which the printer 100 is installed is the Z direction, and the orthogonal direction orthogonal to the Y and Z directions is the X direction. The X, Y and Z directions are orthogonal to each other. In addition, the direction in which the cassette 200 is pulled out from the apparatus main body 101 is the X1 direction, and the mounting direction of the cassette 200 in the apparatus main body 101 is the X2 direction. The X2 direction is the opposite direction to the X1 direction. The X1 direction and the X2 direction are directions along the X direction. The X2 direction is also the sheet P feeding direction. The Y direction is also the width direction of the sheet P. As shown in FIG.

In the first embodiment, the sheet P stacked in the cassette 200 is fed in the X2 direction by the feeding roller 102, then conveyed upward by the sheet conveying section 103, and an image is formed by the image forming section 120. . The image-formed sheet P is conveyed further upward, is heated and pressed by the fixing device 6 , is conveyed in the X1 direction by the discharge roller pair 106 , and is discharged onto the discharge tray 107 . The discharge tray 107 is arranged so as to be inclined upward in the X1 direction. At the downstream end of the discharge tray 107 in the X1 direction, a flat plate-like sheet drop prevention member 108 is arranged so as to be inclined upward in the X1 direction.

In the first embodiment, the apparatus body 101 has an exterior member 110 and the cassette body 201 has an exterior member 210 . An exterior 150 of the printer 100 is configured including the exterior member 110 and the exterior member 210 . That is, each of the exterior members 110 and 210 constitutes part of the exterior 150 . By attaching the cassette 200 to the apparatus main body 101 , the exterior member 210 is integrated with the exterior member 110 .

The drive source 140 generates an operating sound as it operates. That is, the laser scanner 3 and the motor 50 included in the drive source 140 generate operating sounds as they operate. Drive source 140 is surrounded by exterior 150 .

Here, the front portion of the printer 100 is the portion of the printer 100 that is easily accessed by the user, that is, the operation side of the printer 100 . The exterior member 110 has a front surface portion 111 and a rear surface portion 112 spaced apart in the X direction, a side surface portion 113 and a side surface portion 114 spaced apart in the Y direction, and a top surface portion 115. . The front portion 111 is an example of a first wall portion. The front portion 111 is arranged on the side opposite to the image forming portion 120 with the driving source 140 interposed therebetween in the X direction. The front part 111 is arranged at the front part of the printer 100 . The rear portion 112 is arranged at the rear of the printer 100 . The side portions 113 and 114 are arranged on the sides of the printer 100 and are provided continuously with the front portion 111 and the rear portion 112 . The top panel 115 is arranged above the printer 100 and is provided continuously with the front panel 111 , the rear panel 112 , the side panel 113 and the side panel 114 . Top surface 115 includes discharge tray 107 . Any one of the front surface portion 111 , the rear surface portion 112 , the side surface portion 113 , the side surface portion 114 and the top surface portion 115 can swing to open or close the inside of the apparatus body 101 . The exterior member 210 includes a front portion 211 . The front part 211 is arranged at the front part of the printer 100 . The front portion 211 is an example of a fourth wall portion.

By accessing the front portion of the printer 100, the user can easily perform various operations. That is, when the cassette 200 is pulled out from the apparatus main body 101 and when the cassette 200 is attached to the apparatus main body 101, the front portion 211 of the cassette 200 located in the front portion of the printer 100 is operated by the user. The cassette 200 is pulled out from the apparatus main body 101 by being operated by the user in the X1 direction, which is the front of the printer 100, and is attached to the apparatus main body 101 by being operated by the user in the X2 direction opposite to the X1 direction. be done. A switch 30 for turning on/off the power of the printer 100 is provided on the front portion 111 located in the front portion of the printer 100 . A sheet drop prevention member 108 is provided to protrude forward of the printer 100 . In this way, the user's operation targets are concentrated in the front part of the printer 100, so that the interface between the user and the printer 100 is enhanced.

FIG. 3 is a perspective view of the printer 100 in which the interior of the printer 100 according to the first embodiment is seen through. FIG. 3 shows the cassette 200 and the drive source 140. As shown in FIG. In the cassette 200, the sheet P is placed on the sheet stacking area R1 defined by the side regulating plate 221 or the like. The sheet stacking area R1 is an area in which sheets of the maximum size that can be used in the printer 100 can be stacked. A sheet P shown in FIG. 3 is a maximum size sheet. Therefore, in plan view, that is, in the Z direction, the sheet stacking area R1 and the sheets P stacked in the sheet stacking area R1 match. The drive source 140 is arranged so as to overlap the sheet stacking area R1 in plan view, ie, in the Z direction. That is, the drive source 140 is arranged so as to overlap the sheets P stacked in the cassette 200 when viewed in the Z direction. Therefore, the driving source 140 is positioned in the sheet conveying area A1 in the Y direction. The sheet conveying area A1 is an area in the Y direction in the sheet stacking area R1. Such an arrangement makes it easier for sheets P stacked in the cassette 200 to absorb operating noise generated from the drive source 140 . Therefore, the operation sound of the driving source 140 is suppressed from leaking to the outside of the printer 100, and the quietness of the printer 100 is improved. In the first embodiment, the drive source 140 is arranged in the center of the sheet stacking area R1 in the Y direction. As a result, the operating noise generated from the driving source 140 is effectively absorbed by the seat P, and the leakage of the operating noise to the outside of the exterior 150 is effectively suppressed.

As shown in FIG. 1, the device main body 101 has a frame 170 arranged inside the exterior 150 . The frame 170 includes a wall portion 171, a wall portion 172 that is continuous with the wall portion 171, and ribs 173 that are connected to the wall portions 171 and 172 and extend in the X and Z directions. The ribs 173 increase the strength of the walls 171 and 172, that is, the strength of the printer 100. As shown in FIG.

The wall portion 171 is an example of a second wall portion. The wall portion 172 is an example of a third wall portion. The wall portion 172 is arranged so as to overlap with the drive source 140 when viewed in the Z direction. Thereby, the operating noise generated from the drive source 140 can be effectively shielded. The wall portion 172 is arranged at a position overlapping the sheet stacking area R1 when viewed in the Z direction. That is, the wall portion 172 is arranged to face the sheet stacking area R1, that is, the sheet P on the sheet stacking area R1 in the Z direction. The wall portion 172 is spaced apart from the sheet stacking area R1, that is, the sheet P on the sheet stacking area R1 in the Z direction. A wall surface 1722 on the back side of the wall surface 1721 on the side where the driving source 140 is arranged in the wall portion 172 faces the sheet P. As shown in FIG.

The wall portion 171 is arranged between the driving source 140 and the front portion 111 in the X direction. As a result, a space S1 indicated by oblique lines in FIG. 1 is defined between the wall portion 171 and the front portion 111 . FIG. 4 is a perspective view of the printer 100 as seen through the inside of the printer 100 according to the first embodiment. FIG. 4 shows the cassette 200, the driving source 140 and the space S1.

The sound wave energy of the operating sound generated by the drive source 140 is absorbed by the wall portion 171 and attenuated. Further, the sound wave energy of the operation sound is attenuated in the space S1 because the operation sound that has passed through the wall portion 171 is muffled in the space S1. That is, in the space S1, the operating sound is repeatedly reflected between the wall portion 171 and the front portion 111, so that the sound wave energy of the operating sound is attenuated in the space S1. Thus, the space S1 functions as a sound insulation space. As described above, by separating the drive source 140 from the front surface portion 111 by the wall portion 171 and the space S1, it is possible to suppress leakage of operating noise from the printer 100 and improve the quietness of the printer 100. FIG.

In addition, in the printer 100 of the first embodiment, the sheets P are stacked in a cassette 200 that can be pulled out and mounted on the apparatus main body 101 . Therefore, the space S<b>1 is prevented from being opened to the outside of the printer 100 by the cassette 200 attached to the apparatus main body 101 . In this way, the cassette 200 can effectively suppress the sound transmitted to the space S1 from leaking to the outside of the printer 100, and the quietness of the printer 100 is further improved.

In particular, in the first embodiment, it is possible to effectively suppress the leakage of operation sound from the front portion of the printer 100 in which the cassette 200 can be pulled out in the X1 direction by the user. can be suppressed. Here, the X1 direction is also the direction from the wall portion 171 toward the front portion 111 . Note that the exterior 150 of the printer 100 may have ventilation holes communicating with the space S1 or small structural gaps.

The front surface portion 211 and the front surface portion 111 are flush with each other when the cassette 200 is attached to the apparatus main body 101 . As a result, the gap in the exterior 150 is reduced, and the leakage of the operation sound of the drive source 140 to the outside of the exterior 150 is effectively suppressed. The front surface portion 211 is flush with the front surface portion 111 when the wall surface 2111 of the front surface portion 211 is aligned with the wall surface 1111 of the front surface portion 111 in the X direction, and when the wall surface 2111 is aligned with the wall surface 1111 in the X direction. It also includes the case where it shifts in a range smaller than the thickness. Here, the wall surfaces 1111 and 2111 are wall surfaces outside the exterior 150 .

The front surface portion 111 of the exterior member 110 and the wall portion 171 of the frame 170 preferably extend above the upper end of the drive source 140 and below the lower end of the drive source 140 . As a result, the wall portion 171 and the front portion 111 can effectively shield the operating sound of the driving source 140, and the space S1 expands in the vertical direction to effectively attenuate the operating sound. Therefore, the quietness of the printer 100 can be further improved.

The space S1 preferably overlaps the sheet stacking area R1 when viewed in the Z direction. As a result, the operation sound transmitted to the space S1 can be easily absorbed by the sheets P on the sheet stacking area R1, and the leakage of the operation sound transmitted to the space S1 to the outside of the printer 100 can be effectively suppressed. The quietness of the printer 100 can be further improved.

Moreover, it is preferable that the front surface portion 111 of the exterior member 110 and the wall portion 171 of the frame 170 are provided continuously with the top surface portion 115 of the exterior member 110 . As a result, the gap in the upper portion of the space S1 can be reduced, and the quietness of the printer 100 can be further enhanced. Further, since the top surface portion 115 is also used to define the space S1, the space S1 can be widened, and the quietness of the printer 100 can be further improved. In the first embodiment, the discharge tray 107 of the top panel 115 is used to define the space S1.

Further, in the first embodiment, the apparatus main body 101 has a frame 180 which is an example of a connection portion connecting the front surface portion 111 of the exterior member 110 and the wall portion 171 of the frame 170 and extending in the X direction. The frame 180 is a flat member. Therefore, the space S<b>1 in the first embodiment is a space surrounded by the wall portion 171 of the frame 170 , the front portion 111 , the top surface portion 115 and the side portions 113 and 114 of the exterior member 110 , and the frame 180 . Since the frame 170 and the front portion 111 of the exterior member 110 are connected by the frame 180, the strength of the printer 100 is improved. This suppresses the vibration of the printer 100 during the image forming operation.

The frame 180 is arranged to face the sheet stacking area R1, that is, the sheet P on the sheet stacking area R1 in the Z direction. The frame 180 is spaced apart from the sheet stacking area R1, that is, the sheet P on the sheet stacking area R1 in the Z direction. In the first embodiment, the frame 180 is arranged so that the space S1 is a closed space. That is, the space S1 is surrounded by the wall surface 1712 of the wall portion 171, the wall surface 1112 of the front surface portion 111, the wall surface 1072 of the discharge tray 107, the wall surface 1132 of the side surface portion 113, the wall surface 1142 of the side surface portion 114, and the wall surface 1802 of the frame 180. defined by The wall surface 1712 is a wall surface on the back side of the wall surface 1711 on the side where the drive source 140 is arranged in the wall portion 171 . Wall surfaces 1072 , 1112 , 1132 , and 1142 are inner wall surfaces of exterior 150 . A wall surface 1802 is a wall surface on the back side of the wall surface 1801 facing the sheet stacking area R1 in the frame 180 . The frame 180 may be arranged so that the space S1 becomes a closed space, but may have an opening so that the space S1 does not become a closed space.

Space S1 is preferably free of sound-generating members, ie, actuators and members operated by actuators. Actuators include, for example, solenoids. Examples of members operated by actuators include clutches and cooling fans.

From the viewpoint of improving the quietness of the printer 100 , a sound absorbing member may be provided on a part of the exterior 150 , for example, the front portion 111 , or the entire surface of the exterior 150 may be provided with a sound absorbing member. Also, the frame 170 and/or the frame 180 may be provided with a sound absorbing member. Also, a sound absorbing member may be arranged in the space S1.

<Second embodiment>
An image forming apparatus according to the second embodiment will be described. FIG. 5 is a schematic diagram showing a longitudinal section of a printer 100A, which is an example of an image forming apparatus according to the second embodiment. The printer 100A of the second embodiment is the same as the printer 100 of the first embodiment except that the frame 180 is omitted. A hatched space S2 is defined between the wall portion 171 and the front portion 111 in the printer 100A. The operating sound generated by the driving source 140 is transmitted to the space S2 and filled in the space S2. This attenuates the sound wave energy of the operating sound. That is, the space S2 functions as a shielded space. FIG. 6 is a perspective view of the printer 100A in which the interior of the printer 100A according to the second embodiment is seen through. FIG. 6 shows the cassette 200, the driving source 140 and the space S2.

The space S2 is surrounded by a wall surface 1712 of the wall portion 171, a wall surface 1722 of the wall portion 172, a wall surface 1112 of the front portion 111, a wall surface 1072 of the discharge tray 107, a wall surface 1132 of the side portion 113, and a wall surface 1142 of the side portion 114. defined. The space S2 is provided so as to communicate with the sheet stacking area R1 in the cassette 200 attached to the apparatus main body 101 . That is, the lower part of the space S2 communicates with the sheet stacking area R1. As a result, the sheets P stacked in the sheet stacking area R1 can effectively absorb the operating noise generated by the drive source 140 and transmitted to the space S2. As a result, the sound wave energy of the operating sound transmitted to the space S2 can be effectively attenuated, and the quietness of the printer 100A can be further enhanced. In particular, it is possible to effectively suppress the leakage of operation sound from the front portion of the printer 100A from which the cassette 200 can be pulled out in the X1 direction by the user, thereby effectively suppressing the operation sound experienced by the user.

Here, the space S2 communicates with the space S3 in which the driving source 140 and the like are arranged inside the exterior 150 via the sheet stacking area R1. Thus, even if the space S2 and the space S3 communicate with each other, the space S2 functions as a sound insulation space.

Space S2 is preferably free of sound-generating members, ie, actuators and members operated by actuators. Actuators include, for example, solenoids. Examples of members operated by actuators include clutches and cooling fans.

From the viewpoint of improving the quietness of the printer 100A, a sound absorbing member may be provided on a part of the exterior 150, for example, the front portion 111, or the entire surface of the exterior 150 may be provided with a sound absorbing member. Also, the frame 170 may be provided with a sound absorbing member. Also, a sound absorbing member may be arranged in the space S2.

[Example]
An experiment was conducted using the printers 100 and 100A of the first and second embodiments described above. The printer 100 of the first embodiment corresponds to the first embodiment, and the printer 100A of the second embodiment corresponds to the second embodiment. The larger the volume of each of the spaces S1 and S2, the higher the effect.

In the experiment, for comparison, a printer 100X of Comparative Example 1 shown in FIG. 7 was prepared. As shown in FIG. 7, the printer 100X does not have the spaces S1 and S2, and the frame 170X is in contact with the inner wall surface 1112X of the front portion 111X forming part of the exterior of the printer 100X.

Each printer 100, 100A, 100X has a resolution of 600 dpi, 30 sheets/minute (LTR longitudinal feed: process speed of about 222 mm/s), and a life of 100,000 sheets. The printers 100 and 100A were placed in an anechoic chamber with a temperature of 25°C, a humidity of 50%, and 1 atm as an experimental environment, and the operating sound of each of the printers 100, 100A, and 100X when paper was continuously fed for 1 minute was measured. . As the paper, CANON Red Label 80 g/cm ² (paper size A4) was used.

The operating sound measurement method complies with the operating sound level measurement method defined in Japanese Industrial Standard (JIS) Z8731. Using a multi-point traverse sound power level measuring device, the sound power level (dB) was measured as the operating sound level. A sound collecting microphone was installed on the user operation surface side of each of the printers 100, 100A, and 100X, and the operating sound was measured. Ono Sokki's DS3200 was used as an FFT analyzer for the measurement.

Table 1 shows the results of the experiment.

The sound pressure of the operating sound leaking to the outside of the printer 100 of Example 1 is suppressed by 5.41 dB compared to the printer 100X of Comparative Example 1, which does not have the space S1. The sound pressure of the operating sound leaking to the outside of the printer 100A of the second embodiment is suppressed by 2.61 dB compared to the printer 100 of the first embodiment. That is, the sound pressure of the operating sound leaking to the outside of the printer 100A of the second embodiment is suppressed by 8.02 dB compared to the printer 100X of the first comparative example.

From the above experimental results, it was found that in the printer 100 having the space S1, leakage of the operation sound generated by the drive source 140 to the outside from the user operation side of the printer 100 was suppressed. Further, it has been found that the printer 100A having the space S2 more effectively suppresses the leakage of the operation sound generated by the drive source 140 to the outside from the user operation side of the printer 100A.

The present invention is not limited to the embodiments described above, and many modifications are possible within the technical concept of the present invention. Moreover, the effects described in the embodiments are merely enumerations of the most suitable effects resulting from the present invention, and the effects of the present invention are not limited to those described in the embodiments.

In the above-described embodiments, a monochrome electrophotographic printer has been described as an example of an image forming apparatus, but the present invention is not limited to this. For example, the present invention may be applied to a full-color electrophotographic printer having a plurality of process cartridges. Further, for example, the present invention may be applied to an inkjet type image forming apparatus having an inkjet head that forms an image on a sheet by ejecting ink liquid from nozzles as an image forming unit. Further, the present invention may be applied not only to printers, but also to copiers, facsimile machines, and multifunction machines having these functions.

Also, in the above-described embodiment, the case where the cassette 200 is pulled out and mounted in the X direction has been described, but the present invention is not limited to this. The present invention is applicable even if the cassette 200 is pulled out and installed in the Y direction, for example.

DESCRIPTION OF SYMBOLS 100... Printer (image forming apparatus) 101... Apparatus main body 102... Feeding roller (feeding rotating body) 111... Front part (first wall part) 120... Image forming part 140... Drive source 150... Exterior 171 Wall portion (second wall portion) 200 Cassette (sheet stacking portion)

Claims (12)

a device body;
a sheet stacking unit on which sheets are stacked and which can be pulled out and attached to the apparatus main body;
The device main body is
a feeding rotator that feeds the sheets stacked on the sheet stacking unit;
an image forming unit that forms an image on the sheet fed by the feeding rotator;
a drive source arranged so as to overlap a sheet stacking area of the sheet stacking unit in which sheets of the maximum usable size can be stacked in a plan view when the sheet stacking unit is attached to the apparatus main body;
A second housing that constitutes a part of the exterior of the image forming apparatus and is arranged on the side opposite to the image forming section with the drive source interposed therebetween in the orthogonal direction that is orthogonal to the rotation axis direction and the vertical direction of the feeding rotator. 1 wall;
a second wall portion disposed between the drive source and the first wall portion in the orthogonal direction;
a space is defined between the first wall and the second wall;
An image forming apparatus characterized by: The first wall portion and the second wall portion extend above an upper end of the drive source and extend below a lower end of the drive source,
2. The image forming apparatus according to claim 1, wherein: The device main body is
Having a top surface portion that constitutes a part of the exterior,
The first wall portion and the second wall portion are provided continuously with the top surface portion,
3. The image forming apparatus according to claim 1, wherein: The space overlaps the sheet stacking area in a plan view,
4. The image forming apparatus according to claim 1, wherein: The device main body is
Having a third wall portion that is continuous with the second wall portion and overlaps with the drive source in a plan view,
5. The image forming apparatus according to claim 1, wherein: The sheet stacking portion can be pulled out from the apparatus main body in a direction from the second wall portion toward the first wall portion along the orthogonal direction.
6. The image forming apparatus according to claim 1, wherein: The sheet stacking section has a fourth wall that constitutes a part of the exterior and is flush with the first wall when attached to the apparatus main body,
7. The image forming apparatus according to claim 1, wherein: The space is provided so as to communicate with the sheet stacking area in the sheet stacking portion attached to the apparatus main body.
7. The image forming apparatus according to claim 1, wherein: The device main body is
connecting the first wall and the second wall and having a connecting portion extending in the orthogonal direction;
The image forming apparatus according to any one of claims 1 to 8, characterized by: The drive source has a motor,
10. The image forming apparatus according to claim 1, wherein: The image forming unit has an image carrier that carries a toner image,
The drive source has a laser scanner that forms an electrostatic latent image on the image carrier,
The image forming apparatus according to any one of claims 1 to 10, characterized by: An actuator and a member operated by the actuator are not arranged in the space,
The image forming apparatus according to any one of claims 1 to 11, characterized by:

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