Sheet ejection device and image forming apparatus

Abstract

To provide a sheet discharge device with improved cooling efficiency of the sheet loaded on a loading surface and an image formation device equipped with the sheet discharge device.SOLUTION: In a sheet discharge device, a wall having a plurality of holes is provided, wherein the wall comprises an abutment part onto which an upstream end in the direction of discharge of the sheet loaded on a loading surface abuts, the plurality of holes has a first hole formed so as to across an extension line along the loading surface when seen in a width direction orthogonal to the discharge direction and a vertical direction, the first hole has a first end and a second end opposite to the first end, the first end is situated at a side of the loading surface, and an upper end of the first hole at the first end is situated upward of the extension line and a lower end of the first hole at the first end is situated downward of the extension line in the vertical direction.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to a sheet discharging device that discharges a sheet and an image forming apparatus including the same. [Background technology]

[0002] Conventionally, an image forming apparatus has been proposed that discharges sheets on which images have been formed onto a sheet stacking section (see Patent Document 1). The sheets stacked on the sheet stacking section slide along the stacking surface of the sheet stacking section, and are aligned when their rear ends hit a rear end receiving member. If cooling is insufficient, the sheets stacked on the sheet stacking section may stick together due to the weight of the sheets. For this reason, the image forming apparatus described in Patent Document 1 is provided with an air blower fan that generates an air current inside the device body, and an outlet port through which the air current generated by the air blower fan is discharged is provided in the rear end receiving member. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2018-144968 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, the discharge port described in the above Patent Document 1 is provided above the stacking surface of the sheet stacking unit, and there is a risk that the sheets stacked on the stacking surface cannot be sufficiently cooled.

[0005] SUMMARY OF THE PRESENT DISCLOSURE In view of the above, an object of the present invention is to provide a sheet discharge device that improves the efficiency of cooling sheets stacked on a stacking surface, and an image forming apparatus including the same. [Means for solving the problem]

[0006] The present invention provides a sheet ejection device, A device body,a discharge section configured to discharge a sheet in a discharge direction; and a stacking surface on which the sheets discharged by the discharge section are stacked; Air flows from inside the device body to the loading surface. a wall including a plurality of holes, the wall being disposed on the upstream side of the stacking surface in the discharge direction and including an abutment portion against which an upstream end in the discharge direction of a sheet stacked on the stacking surface abuts, the plurality of holes having a first hole portion formed so as to straddle an extension line along the stacking surface when viewed in a width direction perpendicular to the discharge direction and the vertical direction, the first hole portion being Connected to the outside of the device body a first end portion and a second end portion located on the opposite side of the first end portion and farther from the loading surface than the first end portion; And connected to the inside of the device body and a second end portion, and an upper end of the first hole portion at the first end portion is located above the extension line in the vertical direction, and a lower end of the first hole portion at the first end portion is located below the extension line. death , The plurality of holes include an upper hole portion disposed above the first hole portion. It is characterized by: Effect of the Invention

[0007] According to the present invention, it is possible to improve the efficiency of cooling the sheets stacked on the stacking surface. [Brief description of the drawings]

[0008] [Figure 1] 1 is an overall schematic view showing a printer according to a first embodiment. [Diagram 2] FIG. [Diagram 3] FIG. [Figure 4] FIG. 4 is a cross-sectional view showing the air flow around the sheet ejection device. [Diagram 5] FIG. 13 is a perspective view showing a simulated air flow. [Figure 6] FIG. 2 is a cross-sectional view showing a thermal insulation configuration of the printer. [Figure 7] FIG. 1 is a cross-sectional view showing an internal configuration of a printer. [Figure 8] FIG. 11 is a perspective view showing a plurality of holes according to a second embodiment. [Figure 9] FIG. [Figure 10] FIG. 11 is a perspective view showing a loading surface according to a third embodiment. [Figure 11] FIG. 13 is a diagram for explaining a plurality of holes according to the fourth embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] <First embodiment> [Overall structure] First, a first embodiment of the present invention will be described. The printer 100 as an image forming apparatus is an electrophotographic laser beam printer that forms a monochrome toner image. In the following description, the sheet S is a material on which an image is formed by the printer 100, and includes, for example, paper, OHT sheets, etc.

[0010] 1, the printer 100 has a sheet feeding device 4 that feeds stacked sheets, an image forming section 3 that forms an image on the sheet fed by the sheet feeding device 4, and a fixing section 63 that fixes the image transferred to the sheet. The printer 100 also has a sheet discharge device 90 that discharges discharged sheets onto a sheet stacking section 5.

[0011] When an image formation job is output to the printer 100, an image forming process is started by the image forming unit 3 based on image information input from an external computer or the like connected to the printer 100. The image forming unit 3 has a laser scanner 35, a photosensitive drum 31, a charging roller 32, a developing roller 33, and a transfer roller 34. The photosensitive drum 31, the charging roller 32, and the developing roller 33 are made into a cartridge so that they can be replaced as a unit. The photosensitive drum 31 and the transfer roller 34 form a transfer nip T1 as a transfer unit.

[0012] The laser scanner 35 irradiates the photosensitive drum 31 with laser light based on the input image information. At this time, the photosensitive drum 31 is pre-charged by the charging roller 32, and an electrostatic latent image is formed on the photosensitive drum 31 by irradiating it with the laser light. Thereafter, the electrostatic latent image is developed by the developing roller 33, and a monochrome toner image is formed on the photosensitive drum 31.

[0013] In parallel with the above-mentioned image forming process, a sheet S is fed from a sheet feeding device 4. The sheet feeding device 4 has a sheet storage section 41 provided at the bottom of the device body 2 of the printer 100, a pair of regulating plates 42 that regulate the positions of both ends in the width direction of the sheet stored in the sheet storage section 41, and a pickup roller 46. The sheet feeding device 4 also has an inclined surface 43 that regulates the position of the front end of the sheet S stored in the sheet storage section 41, a feed roller 45, and a separation roller 44.

[0014] When the feeding operation of the sheet P is started, the pickup roller 46 descends and contacts the upper surface of the sheet S stored in the sheet storage unit 41. In this state, the pickup roller 46 rotates to feed the sheet S. The fed sheets S are separated one by one by the feed roller 45 and the separation roller 44, and are conveyed to the conveying roller pair 61.

[0015] When the leading edge of the sheet S reaches the pair of conveying rollers 61, the separation roller 44 separates from the feed roller 45. This reduces the sheet conveying speed due to the back tension of the sheet S and the vibration generated when the sheet S passes through the separation nip formed by the feed roller 45 and the separation roller 44.

[0016] Further, the sheet storage unit 41 may be provided with a middle plate capable of supporting a sheet and being raised and lowered, and for example, the middle plate may be raised by inputting an image forming job, and the sheet supported by the middle plate may be brought into contact with the pickup roller 46. Further, the separation roller 44 may be of a torque limiter type or a retard roller type, or may be replaced with a pad or the like.

[0017] The sheet S passes through a pair of conveying rollers 61, and the toner image on the photosensitive drum 31 is transferred to the sheet S at the transfer nip T1 by an electrostatic load bias applied to the transfer roller 34. Residual toner remaining on the photosensitive drum 31 is collected by a cleaning blade (not shown). A fixing section 63 applies a predetermined amount of heat and pressure to the sheet S onto which the toner image has been transferred, melting and fixing (fixing) the toner. The sheet S that has passed through the fixing section 63 is discharged to the sheet stacking section 5 by a pair of discharge rollers 64 serving as a discharge section.

[0018] Next, a case where an image is formed on both sides of the sheet S will be described. A post-fixing sensor 80 is provided between the fixing unit 63 and the discharge roller pair 64. When the rear end of the sheet S with an image formed on the first side is detected by the post-fixing sensor 80, the discharge roller pair 64 rotates in the reverse direction. As a result, the sheet S is sent into a double-sided conveying path 81 by the discharge roller pair 64.

[0019] The sheet S sent into the double-sided conveying path 81 hits a shutter member (not shown) provided in front of the conveying roller pair 82. This corrects the skew of the sheet S. The sheet S is then guided again to the conveying roller pair 61 by the conveying roller pair 82. An image is formed on the second side of the sheet S in the transfer nip T1, and the sheet S is discharged to the sheet stacking unit 5.

[0020] As described above, the path configuration in which the fed sheet S is conveyed upward and then discharged in the direction opposite to the sheet feeding direction (from right to left in FIG. 1) (from left to right in FIG. 1) is a configuration suitable for downsizing the printer 100. However, the path configuration of the printer 100 is not limited to this.

[0021] [Sheet ejection device] Next, the configuration of the sheet discharge device 90 will be described with reference to Fig. 2. The sheet discharge device 90 has a discharge roller pair 64 (see Fig. 1), a sheet stacking section 5, and a hood cover 9. The sheet stacking section 5 has a stacking surface 6 on which the sheets S discharged by the discharge roller pair 64 are stacked, an abutment wall section 7, and a side wall section 8.

[0022] The abutting wall portion 7 as a wall is disposed on the upstream side of the stacking surface 6 in the sheet discharge direction DD. The abutting wall portion 7 faces the stacking surface 6 and extends upward in the vertical direction VD as viewed from the stacking surface 6. The abutting wall portion 7 extends along the vertical direction VD. The extending direction of the abutting wall portion 7 may be parallel to the vertical direction VD or may be inclined with respect to the vertical direction VD. The side wall portions 8 are disposed on both sides of the stacking surface 6 in the width direction WD. The side wall portions 8 extend upward in the vertical direction VD as viewed from the stacking surface 6. The extending direction of the side wall portions 8 may be parallel to the vertical direction VD or may be inclined with respect to the vertical direction VD. The width direction WD is a direction perpendicular to the sheet discharge direction DD and the vertical direction VD as the discharge direction. The width direction WD is parallel to the direction of the rotation shaft of each roller (rotating body) included in the pair of discharge rollers 64.

[0023] The stacking surface 6 is inclined downward toward the upstream in the sheet discharge direction DD. Therefore, the sheet S discharged onto the stacking surface 6 by the discharge roller pair 64 slides down along the stacking surface 6 toward the abutment wall 7. Then, the upstream end of the sheet S in the sheet discharge direction abuts against the abutment wall 7, and the sheet S is aligned in the sheet discharge direction DD.

[0024] An extension tray 12 is provided in a retractable manner on the loading surface 6, and the extension tray 12 can be pulled out in a direction along the loading surface 6. When a relatively long sheet is discharged, the sheet can be supported by the loading surface 6 and the extension tray 12 by pulling out the extension tray 12.

[0025] The abutment wall portion 7 is formed with a discharge port 91 through which the sheet S discharged by the discharge roller pair 64 passes, and a hood cover 9 is disposed above the discharge port 91. The hood cover 9 prevents foreign matter such as dust from entering the inside of the printer 100 through the discharge port 91, and also improves the appearance.

[0026] The abutting wall portion 7 has a reference surface 7a extending along the vertical direction VD, and a rib 11 provided on the reference surface 7a and extending downstream in the sheet discharge direction DD from the reference surface 7a. The rib 11 as the abutting portion is disposed on the upstream side of the stacking surface 6 in the sheet discharge direction DD. It is preferable that the rib 11 is provided at two or more locations in the width direction WD. The upstream end of the sheet S stacked on the stacking surface 6 in the sheet discharge direction DD abuts against the rib 11.

[0027] A plurality of holes 10 are arranged in the reference surface 7a in the width direction WD and the vertical direction VD. The plurality of holes 10 are located below the discharge outlet 91. The plurality of holes 10 are arranged in a position overlapping with an area through which the sheet S passes in the width direction WD. In other words, the plurality of holes 10 are arranged between one end and the other end of the discharge outlet 91 in the width direction WD. In this embodiment, the plurality of holes 10 have a first row 10L aligned along the width direction WD and a second row 10H as upper holes aligned along the width direction WD and provided above the first row 10L.

[0028] [Hole placement] Next, the arrangement of the multiple holes 10 will be described with reference to Fig. 3. Fig. 3 is a cross-sectional view showing the sheet discharge device 90, and one hole in the first row 10L in this cross section is designated as the first hole 10a. Note that each hole in the first row 10L is provided at the same height in the vertical direction VD. In other words, the first hole 10a is provided in multiple locations so as to be aligned along the width direction WD (see Fig. 2).

[0029] As shown in FIG. 3, an extension line along the loading surface 6 is defined as an extension line 15 when viewed in the width direction WD. The first hole portion 10a is formed so as to straddle the extension line 15 in the vertical direction VD when viewed in the width direction WD. In other words, in the vertical direction VD, the upper end 71 of the first hole portion 10a is located above the extension line 15, and the lower end 72 of the first hole portion 10a is located below the extension line 15. More specifically, the first hole portion 10a has a first end portion 501 located on the loading surface 6 side and connected to the outside of the device body 2, and a second end portion 502 located on the opposite side of the first end portion 501 and connected to the inside of the device body 2. In this embodiment, in the vertical direction VD, the upper end 71 of the first hole portion 10a at the first end portion 501 is located above the extension line 15, and the lower end 72 of the first hole portion 10a at the first end portion 501 is located below the extension line 15. The above-mentioned relationship between the extension line 15 and the first hole portion 10a may be satisfied at either the first end portion 501 or the second end portion 502 of the first hole portion 10a.

[0030] In addition, in the sheet discharge direction DD, a gap 16 is provided between the stacking surface 6 and the reference surface 7a of the abutment wall portion 7. In addition, a receiving surface 17 is disposed below the gap 16 as a receiving portion. For example, if a foreign object such as water droplets enters the gap 16, the receiving surface 17 receives the foreign object, thereby preventing the foreign object from falling into the printer 100.

[0031] [Air flow] Next, the air flow around the sheet discharge device 90 will be described with reference to Fig. 4 and Fig. 5. As shown in Fig. 4, the sheet S is usually transported along the arrow SR. At this time, the sheet S is heated in the fixing section 63, and the high-temperature sheet S is discharged to the sheet stacking section 5 by the discharge roller pair 64.

[0032] The air around the sheet stacking section 5 is heated by the heat of the sheets S, and moves laterally (to the right in FIG. 4) along with the conveyance of the sheets S. The heated air generates an ascending air current, which generates an air flow as shown by the arrow 20. This causes the air pressure around the sheet stacking section 5 to decrease.

[0033] Fresh air 21 flows into the sheet stacking section 5, which has thus become negative pressure, through the plurality of holes 10 provided in the abutment wall 7. As described in FIG. 3, the plurality of holes 10 have a first row 10L including the first holes 10a arranged so as to straddle the extension line 15 of the stacking surface 6, and therefore, in particular, the air that has flowed into the sheet stacking section 5 after passing through the first row 10L flows along the stacking surface 6.

[0034] Fig. 5 is a perspective view showing the air flow in a simulation, and sheets are not shown in Fig. 5. Fig. 5 confirms that the air that has passed through the holes 10 and flowed into the sheet stacking section 5 flows along the stacking surface 6. As a result, even if only a relatively small amount of sheets S are stacked on the stacking surface 6, the air can be reliably blown onto the sheets S stacked on the stacking surface 6, and the sheets can be stably and efficiently cooled.

[0035] [Insulation configuration] Next, the heat insulating structure of the printer 100 will be described with reference to Fig. 6. As shown in Fig. 6, the fixing section 63 has a cylindrical fixing rotator 63a made of a belt, a film, or the like, a heating unit 63b disposed inside the fixing rotator 63a, and a pressure roller 63c forming a fixing nip T2 together with the fixing rotator 63a. The heating unit 63b has a heater as a heat generating element, and the fixing nip T2 is heated by the heater.

[0036] In addition, between the fixing unit 63 and the abutting wall 7 in the sheet discharge direction DD, a heat insulating metal plate 150 and a heat insulating resin cover 151 are provided along the outer circumferential surface of the fixing rotor 63a. The heat insulating metal plate 150 as the first wall is made of a metal material, and the heat insulating resin cover 151 as the second wall is made of a resin material. The heat insulating resin cover 151 is arranged with an air layer 152 of about 1 mm between it and the heat insulating metal plate 150. The heat insulating metal plate 150, the air layer 152, and the heat insulating resin cover 151 form a first heat insulating wall 74 extending along the vertical direction VD, and the first heat insulating wall 74 blocks heat from the fixing unit 63 in the direction of the arrow 153.

[0037] A transport guide 155 is disposed between the abutment wall 7 and the heat-shielding resin cover 151 in the sheet discharge direction DD, and the transport guide 155 extends along the sheet discharge direction DD. The abutment wall 7 and the heat-shielding resin cover 151 are connected by the transport guide 155 with as few gaps as possible. The transport guide 155 is made of a resin material. Therefore, heat in the direction of arrow 156 transmitted from a sheet passing above the transport guide 155 is effectively blocked by the transport guide 155 as a second heat-shielding wall.

[0038] This makes it possible to prevent the air in an area 160, indicated by a dashed line, located between the conveying guide 155 and the image forming unit 3 in the vertical direction VD from being heated. Since the air passing through the multiple holes 10 mainly passes through the area 160, the cooling efficiency of the sheet S can be improved by maintaining the area 160 in a low-temperature environment.

[0039] 7 is a cross-sectional view showing the internal configuration of printer 100 according to this embodiment. Printer 100 takes in air from an inflow path (not shown) and stores unheated fresh air in area 172. Area 172 and area 160 are reliably connected by gap 171, and the air that has passed through area 172 and area 160 flows into sheet stacking section 5 through multiple holes 10.

[0040] As described above, in this embodiment, the abutment wall 7 is provided with a plurality of holes 10 having the first holes 10a (as well as the first row 10L) arranged so as to straddle the extension line 15 of the loading surface 6, so that cooling air can flow along the loading surface 6. This makes it possible to improve the cooling efficiency of the sheets and prevent the sheets from sticking to each other, even when, for example, a small number of sheets are loaded on the loading surface 6.

[0041] In particular, in recent years, as print speeds have increased, there has been a trend toward using low-melting-point toners with relatively low melting points. When low-melting-point toners are used, there is a risk of sheets sticking together even in low-end printers with relatively slow print speeds. For this reason, there is a greater demand for improving the cooling efficiency of the discharged sheets. Although it is possible to provide a fan in the printer to generate cooling air for cooling the sheets, it is preferable not to provide a fan, for example, in order to reduce the size, cost, and noise of the device. In this embodiment, the printer 100 is not provided with a fan, but a fan may be provided.

[0042] Here, consider a case where the stacking surface 6 and the abutting wall portion 7 are arranged with no gap in the sheet discharge direction DD. In this case, foreign matter such as water droplets sliding down the stacking surface 6 will enter the inside of the printer 100 through the first hole portion 10a because the first hole portion 10a is arranged to straddle the extension line 15. Therefore, in this embodiment, a gap 16 is provided between the stacking surface 6 and the reference surface 7a of the abutting wall portion 7 in the sheet discharge direction DD. In addition, a receiving surface 17 is provided below the gap 16. This makes it possible to prevent foreign matter such as water droplets from entering the inside of the device through the first hole portion 10a.

[0043] The abutting wall 7 has a reference surface 7a on which the multiple holes 10 are formed, and a rib 11 that abuts against the upstream end of the sheet S. Therefore, when the upper end of the sheet S abuts against the rib 11, a gap is created between the upper end and the multiple holes 10 by the amount of the rib 11, which prevents the multiple holes 10 from being blocked by the sheet S. This makes it possible to maintain good cooling efficiency of the sheet.

[0044] Further, the sheet discharge device 90 defines an area 160 as a passing area by the first heat shielding wall 74, the conveying guide 155, and the abutting wall 7. The air entering the sheet stacking unit 5 through the multiple holes 10 passes through the area 160, but since the area 160 is heat-shielded by the first heat shielding wall 74 and the conveying guide 155, the sheet cooling efficiency can be improved.

[0045] In this embodiment, a duct may be provided to more clearly define the outside air inlet to the region 172. Although the loading surface 6 has a linear planar shape, the shape of the loading surface 6 is not limited to a planar shape. For example, the loading surface 6 may be formed into a curved shape when viewed in the width direction WD. In this case, the extension line 15 is a line following the curved shape of the loading surface 6. More specifically, the extension line 15 is a tangent to the loading surface 6 at the upstream end of the loading surface 6 in the sheet discharge direction DD. In other words, the extension line 15 is a tangent to the loading surface 6 and is tangent to the loading surface 6 at the upstream end of the loading surface 6 in the sheet discharge direction DD. In this embodiment, since the loading surface 6 has a planar shape, the extension line 15 is parallel to the loading surface 6 and passes through the upstream end of the loading surface 6 in the sheet discharge direction DD.

[0046] <Second embodiment> Next, a second embodiment of the present invention will be described, which is a modification of the configuration of the holes in the first embodiment. Therefore, the same configuration as in the first embodiment will be described by omitting illustrations or by assigning the same reference numerals in the drawings.

[0047] 8, the plurality of holes 10Q according to the second embodiment includes a first row 10L, a second row 10H, and a third row 10U. The third row 10U is aligned along the width direction WD and is disposed below the first row 10L.

[0048] 9 is a cross-sectional view showing a sheet discharge device 90B according to the second embodiment, and one hole in the third row 10U in this cross section is designated as the second hole 10b. The holes in the third row 10U are provided at the same height in the vertical direction VD. As shown in FIG. 9, the second hole 10b is located below the first hole 10a and the extension line 15 of the stacking surface 6, and is located at a position corresponding to the rear surface 203 of the stacking surface 6.

[0049] Therefore, the air that has passed through the second hole portion 10b flows along the back surface 203 of the loading surface 6. This air flow is represented by streamlines 204. Therefore, the loading surface 6 can be cooled from both the front and back sides, improving the cooling efficiency of the sheets.

[0050] <Third embodiment> Next, a third embodiment of the present invention will be described, which is a modification of the configuration of the loading surface of the first embodiment. Therefore, the same configurations as those of the first embodiment will be omitted from the drawings or will be described by using the same reference numerals in the drawings.

[0051] 10, the stacking surface 5C according to the third embodiment has a plane 301 and a plurality of grooves 300 recessed below the plane 301 and extending along the sheet discharge direction. The grooves 300 are recessed about 1 mm below the plane 301. The arrangement of the plurality of holes 10 according to the third embodiment is the same as that of the first embodiment.

[0052] As a result, a gap is created below the sheets S loaded on the plane 301 of the loading surface 5C by the size of the grooves 300, and air can pass through the gap. Therefore, the air that has passed through the multiple holes 10 flows along the front and back surfaces of the sheets loaded on the loading surface 5C, improving the cooling efficiency of the sheets. Note that the cooling efficiency of the sheets is improved by setting the width of the plane 301 in the width direction WD to be narrower.

[0053] <Fourth embodiment> Next, a fourth embodiment of the present invention will be described, which is a modification of the configuration of the holes in the first embodiment. Therefore, the same configurations as those in the first embodiment will be described by omitting illustrations or by assigning the same reference numerals in the drawings.

[0054] Fig. 11 is a diagram for explaining a plurality of holes 10X according to the fourth embodiment. The diagram arranged on the left side of Fig. 11 is a schematic diagram showing a first sheet 402, a second sheet 403, and a third sheet 404 loaded on the loading surface 6. The diagram arranged in the center of Fig. 11 is a diagram showing a plurality of holes 10W arranged in an orthogonal alignment pattern according to a comparative example, and the diagram arranged on the right side of Fig. 11 is a diagram showing a plurality of holes 10X arranged in a pattern according to the fourth embodiment.

[0055] As shown in the central drawing in FIG. 11, the multiple holes 10W arranged in the orthogonal alignment pattern according to the comparative example have a first row 101, a second row 102, and a third row 103 aligned in the width direction WD. The holes in the first row 101, the second row 102, and the third row 103 are also aligned in the vertical direction VD and do not overlap each other in the vertical direction VD. That is, in the vertical direction VD, the upper end of the first row 101 is separated from the lower end of the second row 102, and the upper end of the second row 102 is separated from the lower end of the third row 103. The first row 101 includes multiple first holes 10a.

[0056] As shown in the diagram arranged on the right side of FIG. 11, the multiple holes 10X arranged in the pattern according to this embodiment have a fourth row 104, a fifth row 105, and a sixth row 106 each having a multiple number of holes aligned in the width direction WD. The fourth row 104, the fifth row 105, and the sixth row 106 constitute the first row, the second row, and the third row, respectively. In other words, the multiple holes 10X each have a multiple number of holes aligned along the width direction WD, and have multiple rows of holes aligned in the vertical direction VD. The holes in the fourth row 104 and the sixth row 106 are also aligned in the vertical direction VD. The holes in the fifth row 105 are shifted in the width direction WD with respect to the holes in the fourth row 104 and the sixth row 106. In the width direction WD, the holes in the fifth row 105 are located between the holes in the fourth row 104 and the sixth row 106.

[0057] Furthermore, the fifth column 105 overlaps with the fourth column 104 and the sixth column 106 in the vertical direction VD. That is, in the vertical direction VD, the upper end of the fourth column 104 is located at the same position as the lower end of the fifth column 105 or at a higher position than the lower end of the fifth column 105. Furthermore, the upper end of the fifth column 105 is located at the same position as the lower end of the sixth column 106 or at a higher position than the lower end of the sixth column 106. The fourth column 104 includes a plurality of first holes 10a.

[0058] As shown in the diagram on the left side of Fig. 11, a straight line 405 passes through the intersection of the loading surface 6 and the abutment wall 7 and is parallel to the horizontal direction. A straight line 406 passes through the intersection of the second sheet 403 and the abutment wall 7 and is parallel to the horizontal direction. A straight line 407 passes through the intersection of the third sheet 404 and the abutment wall 7 and is parallel to the horizontal direction.

[0059] 11, the straight line 405 extends across the first row 101 and the fourth row 104, and the straight line 407 extends across the second row 102 and the fifth row 105. On the other hand, the straight line 406 passes between the first row 101 and the second row 102 and extends across the fourth row 104 and the fifth row 105.

[0060] In this way, the multiple holes 10W arranged in the orthogonal alignment pattern shown in the center of Fig. 11 have slight gaps between each row in the vertical direction VD, so there are interruptions in the flow of cooling air in the vertical direction VD. On the other hand, the multiple holes 10X arranged in the pattern shown in the right side of Fig. 11 have adjacent rows overlapping each other in the vertical direction VD, so there are no interruptions in the flow of cooling air in the vertical direction VD. This allows the sheet to be cooled more efficiently.

[0061] <Other embodiments> It is preferable that the plurality of holes described above have a maximum opening dimension of 5 mm or less. In each of the above-mentioned embodiments, the holes are circular with a diameter of about 3 mm.

[0062] In any of the above-described embodiments, the plurality of holes may be provided in three or more rows, or may be provided in one row. Each hole is not limited to a round hole, but may be a polygonal hole. Also, each hole may be an oblong hole that is long in the vertical direction VD. Also, the plurality of holes does not have to have two or more holes in each row.

[0063] In addition, in any of the above-described embodiments, the abutting wall portion 7 is provided with the rib 11, but the rib 11 may be omitted. In other words, the reference surface 7a may be used as the abutting portion, and the upstream end of the sheet S may be configured to abut against the reference surface 7a. Also, the gap 16 between the abutting wall portion 7 and the stacking surface 6 may be omitted. Any of the above-described embodiments may be combined with each other in any desired manner. [Explanation of symbols]

[0064] 2: device body / 6: loading surface / 7: wall (butting wall portion) / 7a: reference surface / 10, 10Q, 10W: multiple holes / 10a: first hole portion / 10b: second hole portion / 10H: upper hole portion, second row / 10L: first row / 10U: third row / 11: butting portion, rib / 15: extension line / 16: gap / 17: receiving portion (receiving surface) / 63: fixing portion / 64: discharge portion (pair of discharge rollers) / 71: upper end / 72: lower end / 74: first shield Heat wall / 90, 90B: sheet discharge device / 100: image forming device (printer) / 150: first wall (heat-shielding metal plate) / 151: second wall (heat-shielding resin cover) / 152: air layer / 155: second heat-shielding wall (transport guide) / 160: passing area (area) / 300: groove / 501: first end / 502: second end / DD: discharge direction (sheet discharge direction) / T1: transfer section (transfer nip) / VD: vertical direction / WD: width direction

Claims

1. An apparatus body, a discharge section configured to discharge the sheet in a discharge direction; a stacking surface on which the sheets discharged by the discharge unit are stacked; a wall including a plurality of holes through which air flows from inside the device body to the stacking surface, the wall being disposed upstream of the stacking surface in the discharge direction and including an abutment portion against which an upstream end in the discharge direction of a sheet stacked on the stacking surface abuts; The plurality of holes include a first hole formed so as to straddle an extension line along the loading surface when viewed in a width direction perpendicular to the discharge direction and the vertical direction, the first hole portion has a first end portion connected to the outside of the device body, and a second end portion located on the opposite side of the first end portion and farther from the loading surface than the first end portion, the second end portion connected to the inside of the device body, In the vertical direction, an upper end of the first hole portion at the first end portion is located above the extension line, and a lower end of the first hole portion at the first end portion is located below the extension line, The plurality of holes include an upper hole portion disposed above the first hole portion. A sheet discharging device comprising:

2. A gap is provided between the loading surface and the wall in the discharge direction.

2. The sheet ejection device according to claim 1, wherein the sheet ejection device is a sheet ejection device.

3. Further comprising a receiving portion disposed below the gap, 3. The sheet ejection device according to claim 2.

4. the wall has a reference surface extending along the vertical direction and in which the plurality of holes are formed, the abutment portion is a rib that is provided on the reference surface and extends downstream in the discharge direction from the reference surface, and against which the upstream end of the sheet loaded on the loading surface abuts; 4. The sheet ejection device according to claim 1, wherein the sheet ejection device is a sheet ejection device.

5. The loading surface has a groove extending along the discharge direction.

5. The sheet ejection device according to claim 1, wherein the sheet ejection device is a sheet ejection device.

6. The plurality of holes include the first hole and a second hole disposed below the extension line.

6. The sheet ejection device according to claim 1, wherein the sheet ejection device is a sheet ejection device.

7. When viewed in the discharge direction, each of the plurality of hole portions has a plurality of holes aligned along the width direction and a plurality of rows of hole portions aligned in the vertical direction, The plurality of rows of holes are arranged such that adjacent rows in the vertical direction overlap each other in the vertical direction.

6. The sheet ejection device according to claim 1, wherein the sheet ejection device is a sheet ejection device.

8. the plurality of hole portions include, as viewed in the discharge direction, a first row having a plurality of holes lined up in the width direction, a second row having a plurality of holes lined up in the width direction and positioned above the first row, and a third row having a plurality of holes lined up in the width direction and positioned above the second row, the second row overlaps the first row and the third row in the vertical direction; 6. The sheet ejection device according to claim 1, wherein the sheet ejection device is a sheet ejection device.

9. The abutting portion is configured to restrict movement of the sheets when the sheets loaded on the loading surface move toward the wall.

9. The sheet ejection device according to claim 1, wherein the sheet ejection device is a sheet ejection device.

10. The loading surface is inclined so that sheets loaded on the loading surface move toward the wall.

10. The sheet ejection device according to claim 9.

11. A transfer unit that transfers a toner image onto a sheet; a fixing unit that fixes the toner image transferred by the transfer unit onto a sheet; and a sheet ejection device according to claim 1 , which ejects the sheet that has passed through the fixing unit.

1. An image forming apparatus comprising:

12. a first heat shielding wall disposed between the fixing portion and the wall in the discharge direction and extending along the vertical direction; a second heat shield wall extending in the discharge direction and disposed between the first heat shield wall and the wall in the discharge direction, a passage area through which air flows toward the plurality of holes, is defined by the first heat shielding wall, the second heat shielding wall, and the wall; the first heat shielding wall has a first wall made of a metal material and a second wall made of a resin material and disposed with an air layer between the first wall and the second wall; The second heat shielding wall is made of a resin material.

12. The image forming apparatus according to claim 11.

Images