Image forming device

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A printer 100 comprises: an apparatus body 101; and a cassette 200 that has a sheet P loaded thereon and can be withdrawn from and attached to the apparatus body 101.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

[Technical Field]

[0001] The present invention relates to an image forming apparatus having an image forming unit that forms an image on a sheet. [Background technology]

[0002] An image forming apparatus has an image forming unit that forms an image on a sheet and a drive source that operates when the image forming unit forms an image on the sheet. When the drive source operates, it generates operating noise. For this reason, the drive source is generally provided inside the exterior of the image forming apparatus. Also, as described in Patent Document 1, an exterior that enhances soundproofing by using sound-absorbing materials is known as an exterior for an image forming apparatus. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2007-316351 Summary of the Invention [Problem to be solved by the invention]

[0004] However, even if the drive source is disposed inside the exterior, it is sometimes not possible to completely prevent the operating noise of the drive source from leaking outside the exterior.

[0005] SUMMARY OF THE INVENTION An object of the present invention is to provide an image forming apparatus that is quieter. [Means for solving the problem]

[0006] The image forming apparatus of the present invention includes an apparatus main body and a sheet stacking section on which sheets are stacked and which can be drawn out and attached to the apparatus main body, the apparatus main body including a feeding rotor that feeds the sheets stacked on the sheet stacking section, and an image forming section that forms an image on the sheet fed by the feeding rotor. an image forming unit including at least a photoreceptor that carries a toner image;and when the sheet stacking unit is attached to the apparatus body, the sheet stacking unit is disposed so as to overlap, in a plan view, a sheet stacking area in which sheets of a maximum size usable by the sheet stacking unit can be stacked. , driving the photosensitive member The image forming device has a drive source, a first wall portion that forms part of the exterior of the image forming device and is arranged on the opposite side of the image forming unit across the drive source in a perpendicular direction perpendicular to the direction of the rotation axis of the feeding rotor and the vertical direction, and a second wall portion that is arranged between the drive source and the first wall portion in the perpendicular direction, and a space is defined between the first wall portion and the second wall portion. [Effects of the Invention]

[0007] According to the present invention, quietness can be improved. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a schematic diagram showing a vertical cross section of a printer as an example of an image forming apparatus according to a first embodiment. [Figure 2] 1 is a perspective view of a printer according to a first embodiment. [Figure 3] 1 is a perspective view of a printer according to a first embodiment, showing the interior of the printer. [Figure 4] 1 is a perspective view of a printer according to a first embodiment, showing the interior of the printer. [Figure 5] FIG. 10 is a schematic diagram showing a vertical cross section of a printer as an example of an image forming apparatus according to a second embodiment. [Figure 6] FIG. 10 is a perspective view of a printer according to a second embodiment, showing the interior of the printer. [Figure 7] FIG. 1 is a schematic view showing a vertical cross section of a printer of Comparative Example 1. DETAILED DESCRIPTION OF THE INVENTION

[0009] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

[0010] First Embodiment FIG. 1 is a schematic diagram showing a vertical cross 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 monochrome toner images. The printer 100 includes a device main body 101 and a cassette 200, which is an example of a sheet stacking section that can be pulled out and attached to the device main body 101. Sheets P are stacked in the cassette 200. The sheets P include recording media such as paper, such as plain paper or envelopes, plastic film (OHT) for overhead projectors, and cloth.

[0011] The apparatus main body 101 has a feed roller 102, which is an example of a feeding rotor that feeds the sheets P stacked in the cassette 200, and a sheet conveying section 103 that conveys the sheets P fed by the feed roller 102. The apparatus main body 101 also has an image forming section 120 that forms an image on the sheets P fed by the feed roller 102 and conveyed by the sheet conveying section 103. The apparatus main body 101 also has a fixing device 6 that fixes the image transferred to the sheets P, and a pair of discharge rollers 106 that can discharge the sheets P to a discharge tray 107.

[0012] The cassette 200 has a cassette body 201 as a sheet stacking portion body, a middle plate 202 supported by the cassette body 201 so as to be movable up and down, and a spring member 203 that presses the middle plate 202 upward. When the middle plate 202 is pressed up by the spring member 203, the downstream end of the sheet P stacked on the middle plate 202 is pressed against the feed roller 102.

[0013] When an image formation command is output to the printer 100, an image formation process is started by the image forming unit 120 based on image information input from an external computer or the like connected to the printer 100. The image forming unit 120 has a process cartridge 130 and a transfer roller 5. The process cartridge 130 is equipped with 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 transfer roller 5 form a transfer nip T. The process cartridge 130 is detachable from the apparatus main body 101.

[0014] The apparatus main body 101 also has a drive source 140. The drive source 140 operates when the image forming unit 120 forms an image on a sheet P. In the first embodiment, the drive source 140 includes a motor 50 and a laser scanner 3. The motor 50 is, for example, a brush motor. The motor 50 drives the photosensitive drum 1 to rotate at a predetermined process speed, i.e., a predetermined peripheral speed, in the direction of arrow R via a gear (not shown). In the first embodiment, the object driven by the motor 50 is the photosensitive drum 1, but this is not limited to this. For example, in addition to or instead of the photosensitive drum 1, a rotating body separate from the photosensitive drum 1 may be configured to be driven to rotate by the motor 50.

[0015] The photosensitive drum 1 includes a cylindrical drum base and a photosensitive material provided on the drum base. The drum base is made of, for example, an aluminum alloy or nickel. The photosensitive material is, for example, an OPC (organic photoconductor), amorphous selenium, or amorphous silicon. The surface of the photosensitive drum 1 is uniformly charged to a predetermined polarity and a predetermined potential by a charging roller 2.

[0016] The laser scanner 3 exposes the photosensitive drum 1 by scanning a laser beam E, which is ON / OFF controlled, in the longitudinal direction of the photosensitive drum 1 in accordance with input image information. This removes the charge from the exposed area on the surface of the photosensitive drum 1, forming an electrostatic latent image. Thereafter, the developing roller 41 attaches toner to this electrostatic latent image, thereby developing a monochrome toner image on the photosensitive drum 1. Development methods include jumping development, two-component development, and contact development, and are used in combination with image exposure and reversal development. In this embodiment, the jumping development method is used.

[0017] In parallel with the image formation process, a sheet P stacked in a cassette 200 is fed by a feed roller 102. The sheet conveying section 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 a transfer nip T by a conveying nip N formed by the conveying roller 21 and the driven roller 23. The conveying roller 21 and the driven roller 23 may form a registration roller pair that corrects skew of the sheet P by abutting the leading edge of the sheet P against the conveying nip N.

[0018] The downstream edge of the sheet P conveyed by the conveying nip N is detected by a top sensor 104. Then, the timing at which the downstream edge of the sheet P reaches the transfer nip T is determined based on the position of the top sensor 104, the position of the transfer nip T, and the conveying speed of the sheet P. Thereafter, the toner image on the photosensitive drum 1 is transferred onto the sheet P conveyed by the conveying nip N at the transfer nip T by an electrostatic load bias applied to the transfer roller 5. Residual toner remaining on the photosensitive drum 1 is collected by a cleaning blade 71. The sheet P onto which the toner image has been transferred is subjected to predetermined heat and pressure by a fixing device 6, thereby melting and fixing (fixing) the toner.

[0019] The fixing device 6 has a fixing film 10 with a built-in heater (not shown), and a pressure roller 20 that presses against the fixing film 10. The sheet P that has passed through the fixing device 6 is discharged onto a discharge tray 107 by a pair of discharge rollers 106. During this time, the timing at which the downstream and upstream ends of the sheet P pass by a discharge sensor 105 is detected, and it is determined whether a jam or the like has occurred with the sheet P.

[0020] Although the printer 100 of the first embodiment is configured to be capable of single-sided printing only, it may be configured such that a double-sided conveying path is provided downstream of the fixing device 6 in the sheet conveying direction, and the sheet P with an image formed on its first side is guided again to the transfer nip T by the double-sided conveying path. Also, although the fixing device 6 has been described as having a fixing film 10, the present invention is not limited to this, and the fixing device may have, for example, a fixing roller and a heating roller.

[0021] Here, the direction of the rotation axis L1 of the feed roller 102 is defined as the Y direction, the vertical direction perpendicular to the installation surface on which the printer 100 is installed as the Z direction, and the orthogonal direction perpendicular to the Y and Z directions as the X direction. The X, Y, and Z directions are perpendicular to one another. The X1 direction is the direction in which the cassette 200 is pulled out of the device main body 101, and the X2 direction is the direction in which the cassette 200 is attached to the device main body 101. The X2 direction is the opposite direction to the X1 direction. The X1 and X2 directions are directions along the X direction. The X2 direction is also the feeding direction of the sheet P. The Y direction is also the width direction of the sheet P.

[0022] In the first embodiment, sheets P stacked in cassette 200 are fed in the X2 direction by feed rollers 102, then conveyed upward by sheet conveying unit 103, and an image is formed on the sheet P by image forming unit 120. The sheet P on which the image has been formed is further conveyed upward, then heated and pressed by fixing device 6, and conveyed in the X1 direction by a pair of discharge rollers 106 to be discharged onto discharge tray 107. Discharge tray 107 is disposed so as to incline upward in the X1 direction. A flat sheet drop prevention member 108 is disposed at the downstream end of discharge tray 107 in the X1 direction so as to incline upward in the X1 direction.

[0023] In the first embodiment, the device main body 101 has an exterior member 110, and the cassette main body 201 has an exterior member 210. The exterior member 110 and the exterior member 210 together form an exterior 150 of the printer 100. In other words, each of the exterior members 110 and 210 forms a part of the exterior 150. When the cassette 200 is attached to the device main body 101, the exterior member 210 and the exterior member 110 are integrated together.

[0024] The driving source 140 generates operation sounds in accordance with its operation. That is, the laser scanner 3 and the motor 50 included in the driving source 140 generate operation sounds in accordance with their operation. The driving source 140 is enclosed in an exterior 150.

[0025] Here, the portion of the printer 100 that is easily accessible to the user, i.e., the side that the user operates, is defined as the front of the printer 100. The exterior member 110 has a front surface 111 and a rear surface 112 that are spaced apart in the X direction, side surfaces 113 and 114 that are spaced apart in the Y direction, and a top surface 115. The front surface 111 is an example of a first wall. The front surface 111 is located on the opposite side of the image forming unit 120 in the X direction, with the drive source 140 in between. The front surface 111 is located at the front of the printer 100. The rear surface 112 is located at the rear of the printer 100. The side surfaces 113 and 114 are located on the sides of the printer 100 and are continuous with the front surface 111 and the rear surface 112. The top surface 115 is located at the top of the printer 100, and is continuous with the front surface 111, rear surface 112, side surface 113, and side surface 114. The top surface 115 includes an ejection tray 107. Any of the front surface 111, rear surface 112, side surface 113, side surface 114, and top surface 115 can swing to open or close the inside of the device main body 101. The exterior member 210 includes a front surface 211. The front surface 211 is located at the front of the printer 100. The front surface 211 is an example of a fourth wall.

[0026] The user can easily access the front of the printer 100 to perform various operations. That is, when the cassette 200 is to be pulled out of the device main body 101 or when the cassette 200 is to be inserted into the device main body 101, the user operates a front surface 211 of the cassette 200 located at the front of the printer 100. The cassette 200 is pulled out of the device main body 101 by the user operating it in the X1 direction, which is the front of the printer 100, and is inserted into the device main body 101 by the user operating it in the X2 direction, which is opposite to the X1 direction. In addition, a switch 30 for turning the printer 100 on and off is provided on a front surface 111 located at the front of the printer 100. In addition, a sheet drop prevention member 108 is provided to protrude forward from the printer 100. In this way, by concentrating the objects of operation by the user at the front of the printer 100, the interface between the user and the printer 100 is improved.

[0027] FIG. 3 is a perspective view of the printer 100 according to the first embodiment, showing the interior of the printer 100. FIG. 3 illustrates a cassette 200 and a drive source 140. In the cassette 200, sheets P are placed on a sheet stacking area R1 defined by a side regulating plate 221 and other components. The sheet stacking area R1 is an area capable of stacking sheets of the maximum size usable in the printer 100. The sheet P shown in FIG. 3 is a sheet of the maximum size. Therefore, in a plan view, i.e., in the Z direction, the sheet stacking area R1 and the sheets P stacked in the sheet stacking area R1 coincide with each other. The drive source 140 is arranged to overlap the sheet stacking area R1 in a plan view, i.e., in the Z direction. That is, the drive source 140 is arranged to overlap the sheets P stacked in the cassette 200 in the Z direction. Therefore, the drive source 140 is located in a sheet transport area A1 in the Y direction. The sheet conveying area A1 is an area in the Y direction in the sheet stacking area R1. With this arrangement, the operating noise generated by the drive source 140 is easily absorbed by the sheets P stacked in the cassette 200. This prevents the operating noise of the drive source 140 from leaking outside the printer 100, making the printer 100 quieter. In the first embodiment, the drive source 140 is arranged in the center of the sheet stacking area R1 in the Y direction. This allows the operating noise generated by the drive source 140 to be effectively absorbed by the sheets P, effectively preventing the operating noise from leaking outside the exterior 150.

[0028] 1, the device body 101 has a frame 170 disposed inside the exterior casing 150. The frame 170 includes a wall portion 171, a wall portion 172 continuous with the wall portion 171, and a rib 173 connected to the walls 171 and 172 and extending in the X and Z directions. The rib 173 increases the strength of the walls 171 and 172, and therefore the strength of the printer 100.

[0029] The wall 171 is an example of a second wall. The wall 172 is an example of a third wall. The wall 172 is arranged to extend so as to overlap the driving source 140 when viewed in the Z direction. This makes it possible to effectively block out operating noise generated by the driving source 140. The wall 172 is arranged at a position overlapping the sheet stacking area R1 when viewed in the Z direction. That is, the wall 172 is arranged to face the sheet stacking area R1, i.e., the sheets P on the sheet stacking area R1, in the Z direction. The wall 172 is also arranged at a distance from the sheet stacking area R1, i.e., the sheets 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 faces the sheets P.

[0030] The wall portion 171 is disposed between the drive source 140 and the front surface portion 111 in the X direction. As a result, a space S1, shown by diagonal lines in Fig. 1, is defined between the wall portion 171 and the front surface portion 111. Fig. 4 is a perspective view of the printer 100 according to the first embodiment, showing the interior of the printer 100. Fig. 4 illustrates the cassette 200, the drive source 140, and the space S1.

[0031] The sound wave energy of the operation sound generated by the drive source 140 is absorbed and attenuated by the wall portion 171. Furthermore, the operation sound that passes through the wall portion 171 is trapped in the space S1, and the sound wave energy of the operation sound is attenuated in the space S1. That is, in the space S1, the operation sound is repeatedly reflected between the wall portion 171 and the front surface portion 111, and the sound wave energy of the operation sound is attenuated in the space S1. In this way, the space S1 functions as a soundproof 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 the operation sound from the printer 100, and it is possible to improve the quietness of the printer 100.

[0032] Furthermore, in the printer 100 of the first embodiment, the sheets P are loaded in a cassette 200 that can be pulled out and attached to the device main body 101. Therefore, the space S1 is prevented from being opened to the outside of the printer 100 by the cassette 200 attached to the device main body 101. In this way, the cassette 200 can effectively prevent sound transmitted to the space S1 from leaking to the outside of the printer 100, further improving the quietness of the printer 100.

[0033] In particular, in the first embodiment, it is possible to effectively prevent operating noise from leaking from the front of the printer 100, where the cassette 200 can be pulled out in the X1 direction by the user, and to effectively suppress the operating noise experienced by the user. Here, the X1 direction is also the direction from the wall 171 toward the front surface 111. Note that the exterior 150 of the printer 100 may have ventilation holes or small structural gaps that communicate with the space S1.

[0034] When cassette 200 is attached to device main body 101, front surface 211 is flush with front surface 111. This reduces gaps in exterior casing 150, effectively preventing operating noise from drive source 140 from leaking outside exterior casing 150. "Front surface 211 being flush with front surface 111" includes cases where wall surface 2111 of front surface 211 is aligned with wall surface 1111 of front surface 111 in the X direction, and cases where wall surface 2111 is misaligned with wall surface 1111 in the X direction by an amount smaller than the thickness of front surface 211. Here, wall surfaces 1111, 2111 are outer wall surfaces of exterior casing 150.

[0035] It is preferable that the front surface 111 of the exterior member 110 and the wall surface 171 of the frame 170 extend above the upper end of the drive source 140 and below the lower end of the drive source 140. This allows the wall surface 171 and the front surface 111 to effectively block out the operating noise of the drive source 140, and also allows the space S1 to expand in the vertical direction, effectively attenuating the operating noise. This further improves the quietness of the printer 100.

[0036] It is preferable that the space S1 overlaps with the sheet stacking area R1 when viewed in the Z direction. This makes it easier for the operating noise transmitted to the space S1 to be absorbed by the sheets P on the sheet stacking area R1, effectively preventing the operating noise transmitted to the space S1 from leaking outside the printer 100, and further improving the quietness of the printer 100.

[0037] Furthermore, it is preferable that the front surface 111 of the exterior member 110 and the wall portion 171 of the frame 170 are provided contiguous with the top surface 115 of the exterior member 110. This reduces the gap at the top of the space S1, further improving the quietness of the printer 100. Furthermore, the top surface 115 is also used to define the space S1, so the space S1 can be made larger, further improving the quietness of the printer 100. In the first embodiment, the discharge tray 107 of the top surface 115 is used to define the space S1.

[0038] In the first embodiment, the device main body 101 includes a frame 180 that connects the front surface 111 of the exterior member 110 and the wall portion 171 of the frame 170 and is an example of a connecting portion extending in the X direction. The frame 180 is a flat plate-shaped member. Therefore, the space S1 in the first embodiment is a space surrounded by the wall portion 171 of the frame 170, the front surface 111, the top surface 115, and the side surfaces 113 and 114 of the exterior member 110, and the frame 180. Since the frame 170 and the front surface 111 of the exterior member 110 are connected by the frame 180, the strength of the printer 100 is improved. This reduces vibration of the printer 100 during image formation operations.

[0039] The frame 180 is disposed facing the sheet stacking area R1, i.e., the sheets P on the sheet stacking area R1, in the Z direction. The frame 180 is disposed at a distance from the sheet stacking area R1, i.e., the sheets P on the sheet stacking area R1, in the Z direction. In the first embodiment, the frame 180 is disposed so that the space S1 is a closed space. That is, the space S1 is defined by a wall surface 1712 of the wall portion 171, 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, a wall surface 1142 of the side portion 114, and a wall surface 1802 of the frame 180. 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 disposed in the wall portion 171. The walls 1072, 1112, 1132, and 1142 are inner wall surfaces of the exterior casing 150. The wall surface 1802 is a wall surface on the back side of the wall surface 1801 that faces the sheet stacking area R1 in the frame 180. The frame 180 may be arranged so that the space S1 is a closed space, or may have an opening so that the space S1 is not a closed space.

[0040] It is preferable that no sound-generating components, i.e., actuators or components operated by actuators, are placed in the space S1. Examples of actuators include solenoids. Examples of components operated by actuators include clutches and cooling fans.

[0041] To improve the quietness of the printer 100, a sound-absorbing material may be provided on a portion of the exterior 150, such as the front surface 111, or on the entire surface of the exterior 150. A sound-absorbing material may also be provided on the frame 170 and / or the frame 180. A sound-absorbing material may also be disposed in the space S1.

[0042] Second Embodiment An image forming apparatus according to a second embodiment will now be described. FIG. 5 is a schematic diagram showing a vertical cross 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 printer 100 of the first embodiment without the frame 180. The other configuration is the same as that of the printer 100 of the first embodiment, and therefore a description thereof will be omitted. In the printer 100A, a space S2, indicated by diagonal lines, is defined between the wall portion 171 and the front portion 111. Operational noise generated by the drive source 140 propagates into the space S2 and is trapped there. This attenuates the sound wave energy of the operation noise. In other words, the space S2 functions as a shielding space. FIG. 6 is a perspective view of the printer 100A according to the second embodiment, showing the interior thereof. FIG. 6 illustrates the cassette 200, the drive source 140, and the space S2.

[0043] The space S2 is defined 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. The space S2 is provided to communicate with the sheet stacking area R1 when the cassette 200 is attached to the device main body 101. That is, the lower part of the space S2 communicates with the sheet stacking area R1. This allows the sheets P stacked in the sheet stacking area R1 to effectively absorb the operating noise generated by the drive source 140 and transmitted to the space S2. This effectively attenuates the sound wave energy of the operating noise transmitted to the space S2, further improving the quietness of the printer 100A. In particular, it is possible to effectively prevent operating noise from leaking from the front of the printer 100A, which allows the user to pull out the cassette 200 in the X1 direction, and it is possible to effectively reduce the operating noise experienced by the user.

[0044] Here, the space S2 communicates with a space S3 in which the drive source 140 and the like are disposed through the sheet stacking area R1 inside the exterior casing 150. In this way, even though the space S2 and the space S3 communicate with each other, the space S2 functions as a soundproof space.

[0045] It is preferable that no sound-generating components, i.e., actuators or components operated by actuators, are placed in the space S2. Examples of actuators include solenoids. Examples of components operated by actuators include clutches and cooling fans.

[0046] To improve the quietness of printer 100A, a sound-absorbing material may be provided on a part of exterior 150, such as front surface 111, or on the entire surface of exterior 150. A sound-absorbing material may also be provided on frame 170. A sound-absorbing material may also be disposed in space S2.

[0047] [Example] Experiments were conducted using the printers 100, 100A of the first and second embodiments described above. The printer 100 of the first embodiment corresponds to Example 1, and the printer 100A of the second embodiment corresponds to Example 2. The larger the volume of each space S1, S2, the greater the effect, and they were set to a size that occupies approximately 15% of the internal volume of the exterior casing 150.

[0048] For comparison in the experiment, a printer 100X of Comparative Example 1 shown in Fig. 7 was prepared. As shown in Fig. 7, the printer 100X does not have spaces S1 and S2, and the frame 170X is in contact with an inner wall surface 1112X of a front surface 111X that constitutes part of the exterior of the printer 100X.

[0049] Each of the printers, 100, 100A, and 100X, has a resolution of 600 dpi, a speed of 30 pages per minute (LTR vertical feed: process speed approximately 222 mm / s), and a lifespan of 100,000 pages. The test environment was an anechoic chamber with a temperature of 25°C, humidity of 50%, and pressure of 1 atmosphere, and the operating noise of each of the printers, 100, 100A, and 100X, was measured when paper was continuously fed for 1 minute. The paper used was CANON Red Label 80g / cm 2 (Paper size A4 was used.

[0050] The operating noise measurement method complies with the operating noise level measurement method stipulated in the Japanese Industrial Standard (JIS) Z 8731. A multi-point traverse sound power level measurement device was used to measure the sound power level (dB) as the operating noise level. A sound-collecting microphone was installed on the user operation surface of each printer 100, 100A, and 100X to measure the operating noise. For the measurements, an Ono Sokki DS3200 was used as the FFT analyzer.

[0051] The results of the experiment are shown in Table 1. [Table 1]

[0052] The sound pressure of the operation sound leaking to the outside of the printer 100 of Example 1 is reduced 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 operation sound leaking to the outside of the printer 100A of Example 2 is reduced by 2.61 dB compared to the printer 100 of Example 1. In other words, the sound pressure of the operation sound leaking to the outside of the printer 100A of Example 2 is reduced by 8.02 dB compared to the printer 100X of Comparative Example 1.

[0053] From the above experimental results, it was found that the printer 100 having the space S1 can suppress the leakage of the operating sound generated by the drive source 140 from the user operation side of the printer 100 to the outside. Furthermore, it was found that the printer 100A having the space S2 can even more effectively suppress the leakage of the operating sound generated by the drive source 140 from the user operation side of the printer 100A to the outside.

[0054] It should be noted that the present invention is not limited to the above-described embodiments, and many modifications are possible within the technical concept of the present invention. Furthermore, the effects described in the embodiments are merely a list of the most preferable effects resulting from the present invention, and the effects of the present invention are not limited to those described in the embodiments.

[0055] In the above embodiment, 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 multiple process cartridges. Furthermore, the present invention may be applied to an inkjet image forming apparatus having an inkjet head as an image forming unit that forms an image on a sheet by ejecting ink liquid from nozzles. Furthermore, the present invention is not limited to printers, but may also be applied to copiers, facsimile machines, and multifunction machines having these functions.

[0056] In the above embodiment, the case where the cassette 200 is pulled out and inserted in the X direction has been described, but this is not limiting. The present invention is also applicable to cases where the cassette 200 is pulled out and inserted in the Y direction, for example. [Explanation of symbols]

[0057] 100... printer (image forming apparatus), 101... apparatus main body, 102... feeding roller (feeding rotating body), 111... front portion (first wall portion), 120... image forming unit, 140... driving source, 150... exterior, 171... wall portion (second wall portion), 200... cassette (sheet stacking portion)

Claims

1. A device body, a sheet stacking section on which sheets are stacked and which can be drawn out and attached to the device body, The device body includes: a feeding rotor that feeds the sheets stacked in the sheet stacking section; an image forming unit that forms an image on the sheet fed by the feeding rotary body, the image forming unit including at least a photoreceptor that carries a toner image; a drive source that is arranged to overlap, in a plan view, a sheet stacking area of the sheet stacking unit that can stack sheets of the maximum size that can be used by the sheet stacking unit when the sheet stacking unit is attached to the apparatus main body, and that drives the photosensitive member; a first wall portion that constitutes a part of an exterior of the image forming apparatus and is disposed on the opposite side of the image forming unit across the drive source in a direction perpendicular to the direction of the rotation axis of the feeding rotor and the vertical direction; a second wall portion disposed between the driving 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:

2. the first wall portion and the second wall portion extend upward beyond an upper end of the driving source and extend downward beyond a lower end of the driving source; 2. The image forming apparatus according to claim 1, wherein the image forming apparatus is a recording medium.

3. The device body includes: 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 image forming apparatus is a recording medium.

4. the space overlaps with the sheet stacking area in a plan view; 4. The image forming apparatus according to claim 1, wherein the image forming apparatus is a recording medium.

5. The device body includes: 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 image forming apparatus is a recording medium.

6. the sheet stacking portion is retractable 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 image forming apparatus is a recording medium.

7. the sheet stacking section forms a part of the exterior and has a fourth wall section that is flush with the first wall section when the sheet stacking section is attached to the apparatus body.

7. The image forming apparatus according to claim 1, wherein the image forming apparatus is a recording medium.

8. the space is provided so as to communicate with the sheet stacking area when the sheet stacking section is attached to the apparatus main body; 7. The image forming apparatus according to claim 1, wherein the image forming apparatus is a recording medium.

9. The device body includes: a connecting portion that connects the first wall portion and the second wall portion and extends in the perpendicular direction; 9. The image forming apparatus according to claim 1, wherein the image forming apparatus is a recording medium.

10. No actuator or member operated by the actuator is disposed in the space.

10. The image forming apparatus according to claim 1, wherein the image forming apparatus is a recording medium.

Images