JP7679226B2 - Image forming device - Google Patents

Description

The present invention relates to an image forming device that forms an image on a sheet.

The image forming device has a discharge roller as a discharge means for discharging a recording medium as a sheet, and a discharge tray on which the discharged recording medium is stacked. In Patent Document 1, a convex portion extending in the discharge direction is provided at the center of the width direction perpendicular to the discharge direction. The discharge tray has recesses on both sides of the width direction of the convex portion. The recesses allow hands to be placed under the stacked sheets, making it easy to remove the sheets stacked on the discharge tray from the discharge tray.

JP 2012-63372 A

In the configuration of Patent Document 1, the sheets can be easily removed from the discharge tray, but the recesses make the stacked state of the sheets unstable. In other words, it is not possible to achieve both easy removal of the sheets and stable stacking of the sheets at the same time.

The image forming apparatus of the present invention has an image forming section which forms an image on a sheet, a discharge section which discharges the sheet formed by the image forming section, and a stacking section on which the sheets transported in a discharge direction and discharged by the discharge section are stacked, the stacking section having a first region including a first support section which supports a sheet and a first recess which is provided at one end in a sheet width direction perpendicular to the discharge direction and recessed downward, a second region including a second support section which supports a sheet and is wider than the width of a maximum size sheet in the sheet width direction, the second region being positioned downstream in the discharge direction from the first region and including an inclined surface portion provided at the one end in the sheet width direction, a third support section which supports a sheet, and a second recess which is provided at the one end in the sheet width direction and recessed downward, and a third region arranged downstream of the second region in the discharge direction, the inclined portion inclines downward as it approaches the one side in the sheet width direction, the second recess includes a bottom which becomes downward as it approaches the one side in the sheet width direction, the bottom of the second recess and the inclined portion are arranged to be continuous in the discharge direction, and when the maximum size sheet is discharged to the stacking section by the discharge section and supported on the stacking section, the maximum size sheet supported on the stacking section overlaps with the first recess when viewed from above, and the maximum size sheet overlaps with the second recess, and the one side end of the second support portion in the sheet width direction is on the one side of the one side end of the maximum size sheet in the sheet width direction.

The present invention allows for easy removal of sheets while also providing stable sheet loading.

1 is a cross-sectional view showing an entire image forming apparatus according to an embodiment. FIG. Top view of the ejection tray. FIG. FIG. 13 is a perspective view showing a modified example of the discharge tray. 5A and 5B are diagrams for explaining configurations of a first recess and a first support portion. 6A and 6B are diagrams for explaining the configuration of a second recess and a third support portion.

(Overall configuration of image forming apparatus)
<Image forming apparatus>
FIG. 1 is a cross-sectional view of an image forming apparatus 100 according to the present invention, which employs an intermediate transfer tandem system in which image forming units for four colors are arranged side by side on an intermediate transfer belt.

The image forming apparatus 100 includes an image reading device 920 that reads an image of an original document, an image forming section 910 that forms an image on a sheet based on the image read by the image reading device 920, and an internal discharge section 190 to which the sheet on which the image has been formed by the image forming section 910 is discharged.

The image forming unit 910 has a cassette 111 at the bottom. Sheets S are stored in a stacked manner in the cassette 111, which is a storage device. Side regulation members are arranged in the cassette 111 to regulate the position of the sheet in the width direction perpendicular to the feeding direction by contacting the edge of the sheet. The side regulation members position the sheet so that its width position is at a regular position in the cassette 111. In detail, the movable side regulation members position the sheet in the cassette 111 so that the edge is located at a regular position determined for each sheet size.

The sheets stored in the cassette 111 are fed by the sheet feeding means 110 in accordance with the image formation timing of the image forming device. The sheet S fed by the sheet feeding means 110 passes through a transport path and is transported to the skew correction device 120. After skew correction and timing correction are performed in the skew correction device 120, the sheet S is sent to the secondary transfer unit 130. The secondary transfer unit 130 is a toner image transfer nip for the sheet S formed by the substantially opposing secondary transfer inner roller 131 and secondary transfer outer roller 132, and transfers the toner image to the sheet S by applying a predetermined pressure force and electrostatic load bias.

The process of conveying the sheet S to the secondary transfer unit 130 described above will be described below. The image forming unit 140 is mainly composed of a photoconductor 141, an exposure device 142, a developing device 143, and a primary transfer device 144. The exposure device 142 emits light based on the signal of the image information sent to the photoconductor 141, whose surface has been uniformly charged in advance by a charging device, and a latent image is formed through a diffraction device or the like as appropriate. The electrostatic latent image thus formed on the photoconductor 141 is developed by the developing device 143 to form a toner image on the photoconductor 141. After that, a predetermined pressure force and an electrostatic load bias are applied by the primary transfer device 144, and the toner image is transferred onto the intermediate transfer belt 145. In the case of FIG. 1, the image forming unit 140 described above is provided with four sets of yellow Y, magenta M, cyan C, and black Bk.

Next, the intermediate transfer belt 145 will be described. The intermediate transfer belt 145 is driven to be transported in the direction of arrow A in FIG. 1. Therefore, the aforementioned Y, M, C, and Bk image forming devices process the images in parallel. The image forming process for each color is performed at a timing that overlaps with the upstream toner image that has been primarily transferred onto the intermediate transfer belt 145. As a result, a full-color toner image is finally formed on the intermediate transfer belt 145 and transported to the secondary transfer unit 130.

Through the above-described conveying process and image forming process of the sheet S, a full-color toner image is secondarily transferred onto the sheet S in the secondary transfer section 130. The sheet S is then conveyed to the fixing device 150. The fixing device 150 applies a predetermined pressure force by a roller or belt that is substantially opposed to the sheet S, and a heating effect by a heat source such as a heater, to melt and fix the toner on the sheet S. The heat source section 151 that applies this heating effect is disposed on the same side as the image forming surface of the sheet S, and the pressure section 152 that applies the pressure force is disposed on the opposite side. The sheet S having the fixed image thus obtained is discharged onto the discharge tray 170 by the discharge roller 161, or is branched by the first switching flapper 153 and conveyed toward the reversing roller 162. The sheet S conveyed to the reversing roller 162 is conveyed to the double-sided conveying path 180 by the reversing operation of the reversing roller 162 after the rear end of the sheet S passes the second switching flapper 154. During this reversal operation, the sheet S that temporarily flies out of the machine is supported by the upper discharge tray 172. After passing through the double-sided conveying path 180, the sheet S is again subjected to skew correction and timing correction by the skew correction device 120, and then sent to the secondary transfer section 130, where the image on the second side is transferred and fixed by the fixing device 150. The sheet S is then discharged onto the discharge tray 170 for double-sided printing. The discharge tray 170 on which the discharged sheet S is stacked has an upward slope from the upstream to the downstream in the discharge direction of the sheet S. Therefore, the discharged sheet S moves upstream in the discharge direction due to the weight of the sheet S itself, and the rear end (upstream end) of the sheet hits the rear end wall 401 and is aligned.

The discharge section 160 discharges the sheet S to the internal discharge section 190 by the discharge rollers 161. The sheet discharged by the discharge rollers 161 of the discharge section 160 is stacked on the discharge tray 170. The discharge tray 170 is part of the cover of the image forming section 910. A pressing member 202 that is supported so as to be freely rotatable is disposed above the discharge tray 170. The pressing member 202 presses the sheets stacked on the discharge tray 170 from above.

In addition to the discharge tray 170, the internal discharge section 190 is also provided with an upper discharge tray 172. The reversing roller 162 rotates without reversing, and the sheets are discharged to the upper discharge tray 172 and are stacked on the upper discharge tray 172.

The user removes the sheets that have been discharged onto the discharge tray 170 and stacked on the discharge tray 170. In FIG. 1, the user inserts his/her hand into the internal discharge section 190 from the front side of the device to remove the sheets that have been discharged onto either the discharge tray 170 or the upper discharge tray 172 in the internal discharge section 190.

Operation unit 303 has buttons arranged thereon that allow the user to instruct the start of an image forming operation. The user also inputs various settings for the image forming device via operation unit 303. The status of the image forming device is displayed on operation unit 303 to inform the user.

<Configuration of output tray>
The shape of the discharge tray 170 will be described with reference to Fig. 1 to Fig. 4. Fig. 2 is a schematic perspective view of the discharge tray 170. Fig. 3 is a schematic plan view of the discharge tray 170. Fig. 4 is a schematic front view of the discharge tray 170.

In FIG. 2, discharge tray 170 holds sheets that have been conveyed in discharge direction 302 by discharge rollers 161 and discharged. Discharge tray 170 has projections and recesses to facilitate easy removal of stacked sheets. In this embodiment, discharge tray 170 has a first recess 170a provided on the upstream side in discharge direction 302 and a second recess 170c provided on the downstream side in discharge direction 302 as projections and recesses.

The discharge tray 170 includes a first region 201, a second region 202, and a third region 203 in order from the upstream side of the discharge direction 302. The first region 201 includes a first support portion 204 that supports a sheet and a first recess 170a. The first recess 170a is disposed at the end of the first region 201 on the front 301 side of the device. The first recess 170a extends in the discharge direction 302 to the upstream end of the discharge tray 170 in the discharge direction 302, that is, to a position facing the rear end wall 401. The discharge tray 170 includes a second region 202 downstream of the first region 201 in the discharge direction 302, and the second region 202 has a second support portion 205 and a slope portion 170b that support a sheet. The discharge tray 170 includes a third region 203 downstream of the second region 202 in the discharge direction 302. The third region 203 has a third support portion 206 that supports the sheet and a second recess 170c. The second recess 170c is located at the end of the third region 203 on the device front 301 side.

The front of the device 301 here is one side in the sheet width direction perpendicular to the discharge direction 302, and is the side where a user who operates the operation unit 303 stands. In other words, the operation unit 303 is positioned so that the user can operate 301 from the front of the device, which is one side in the sheet width direction.

The first support portion 204, the second support portion 205, and the third support portion 206 for supporting the sheet are provided with a plurality of ribs 402 aligned in the sheet width direction, the ribs 402 extending continuously along the discharge direction 302 so as to span the first support portion 204, the second support portion 205, and the third support portion 206.

The first recess 170a is recessed below the first support portion 204 so that a user can insert his/her hand or finger under the sheet supported by the discharge tray 170 from the front 301 of the device. In other words, the first recess 170a supports the sheet on the discharge tray 170 with the end of the sheet on the front 301 side of the device protruding from the first support portion 204. The first recess 170a is formed so that the width D2 in the discharge direction 302 of the part of the first recess 170a on the front 301 side of the device is larger than the width D1 of the part of the first recess 170a on the rear side of the device. A tapered portion 211 is disposed at a position on the rear side of the first recess 170a close to the first support portion 204. The tapered portion 211 is inclined with respect to the horizontal plane so as to be higher toward the rear of the device, i.e., so as to be closer to the first support portion 204 in the height direction toward the rear of the device. The tapered portion 211 guides the hand to a place where it is easy to grasp the sheet.

The arrangement of the first recess 170a will be described in detail below. The first recess 170a is arranged so that when a sheet S1 of the maximum size in the sheet width direction (hereinafter referred to as the maximum sheet) is discharged to the discharge tray 170 and supported by the discharge tray 170, it overlaps with the maximum sheet S1 when viewed from above. FIG. 6 is a cross-sectional view of the first recess 170a and the first support portion 204 when cut along a plane extending parallel to the front-rear direction of the device and vertically. The depth of the first recess 170a is set to be lower than the end of the maximum sheet S1 on the front 301 side of the device supported by the rib 402 of the first support portion 204. In this embodiment, the shape of the first recess 170a is set so that the difference H1 in height between the end of the maximum sheet S1 on the front 301 side of the device supported by the first support portion 204 and the bottom surface of the first recess 170a is 30 mm. To make it easier to grasp the largest sheet S1, it is preferable to configure the first recess 170a so that the difference H1 in height between the end of the largest sheet S1 supported by the first support portion 204 on the front 301 side of the device and the bottom surface of the first recess 170a is 10 mm or more.

In this way, the end of the sheet supported by the first support portion 204 on the front 301 side of the device protrudes from the first support portion 204 toward the front 301 of the device. Therefore, when removing the sheet stacked on the discharge tray 170, the end of the sheet can be grasped by touching the bottom surface and the top surface of the sheet with fingers, making it possible to easily remove the sheet.

As shown in FIG. 3, when a sheet S2 (hereinafter referred to as a smallest sheet) having the smallest size in the sheet width direction is discharged to the discharge tray 170 and supported by the discharge tray 170, the first recess 170a is arranged so as to overlap with the smallest sheet S2 when viewed from above. Therefore, even if it is the smallest sheet S2, it is possible to easily grab the sheet by hand and remove it from the discharge tray 170.

In this embodiment, the shape of the first recess 170a is set so that the difference in height between the end of the smallest sheet S2 supported by the first support portion 204 on the device front 301 side and the bottom surface of the first recess 170a is 20 mm. To make it easier to grasp the smallest sheet S2, it is preferable to configure the first recess 170a so that the difference in height between the end of the smallest sheet S2 supported by the first support portion 204 on the device front 301 side and the bottom surface of the first recess 170a is 10 mm or more.

As described above, the sheet is positioned in the correct position in the cassette 111 in the sheet width direction by the side regulating member of the cassette 111. The above-mentioned case where the sheet is discharged to the discharge tray 170 and supported by the discharge tray 170 means the case where the sheet is supported (stacked) on the discharge tray 170 without being displaced in the sheet width direction from the position where it was positioned by the side regulating plate. Furthermore, the sheet with the maximum size in the sheet width direction (maximum sheet) is the sheet with the largest size in the sheet width direction that the image forming device can form an image on and discharge to the stacking section. Furthermore, the sheet with the smallest size in the sheet width direction (minimum sheet) is the sheet with the smallest size in the sheet width direction that the image forming device can form an image on and discharge to the stacking section.

Next, the second recess 170c will be described. The second recess 170c is positioned so that when a sheet S1 of the maximum size in the sheet width direction (hereinafter referred to as the maximum sheet) is discharged and stacked on the discharge tray 170, the second recess 170c overlaps with the maximum sheet S1 when viewed from above. The second recess 170c supports the sheet on the discharge tray 170 with the end of the sheet on the device front 301 side protruding from the third support portion 206.

Figure 7 is a cross-sectional view of the second recess 170c and the third support portion 206 when cut along a plane extending parallel and vertically to the front-rear direction of the device. The depth of the second recess 170c is set to be lower than the end of the largest sheet S1 supported by the rib 402 of the third support portion 206 on the front 301 side of the device. In this embodiment, the shape of the second recess 170c is set so that the height difference H2 between the end of the largest sheet S1 supported by the third support portion 206 on the front 302 side of the device and the second recess 170c is 20 mm. In order to make it easier to grasp the sheet, it is preferable to configure the second recess 170c so that the height difference H2 between the end of the largest sheet S1 supported by the third support portion 206 on the front 301 side of the device and the bottom surface of the second recess 170c is 10 mm or more.

As described above, since there is a gap in the height direction between the end of the largest sheet S1 on the front 301 side of the device and the bottom surface of the second recess 170c, even when the largest sheet S1 is stacked on the discharge tray 170, the bottom and top surfaces of the sheet can be touched with the fingers to grasp the sheet. The bottom surface of the second recess 170c includes a curved portion that is upwardly curved toward the back of the device, that is, that approaches the third support portion 206 in the height direction toward the back of the device. Specifically, the bottom of the second recess 170c is an arc-shaped surface. As described above, the shape of the second recess 170c allows the finger to be guided by the second recess 170c to a place where it is easy to grasp the sheet when the finger is inserted.

In addition, in the direction parallel to the conveying direction (discharge direction), as shown in FIG. 4, the second recess 170c is disposed downstream of half the overall size of the discharge tray 170 so that d1≦d2.

Next, the second region 202 will be described with reference to FIGS. 2 and 3. The second support portion 205 of the second region 202 is wider than the width of the largest sheet S1 in the sheet width direction so that the bottom surface of the sheet can be supported over the entire area of the largest sheet S1 in the sheet width direction. When the largest sheet S1 is discharged and stacked on the discharge tray 170 in the sheet width direction, the end 232 of the second support portion 205 on the front side of the device is arranged to be closer to the front side of the device than the end of the largest sheet S1 on the front side of the device. As shown in FIGS. 2 and 3, the end 232 on the front side of the device of the second support portion 205 is closer to the front 301 side of the device than the end 231 on the front side of the device of the first support portion 204. The end 232 on the front side of the device of the second support portion 205 is closer to the front 301 side of the device than the end 233 on the front side of the device of the third support portion 206. As shown in FIG. 2, the inclined surface 170b on the front side of the device in the second region 202 is continuous with the second recess 170c in the ejection direction 302. The inclined surface 170b and the second recess 170c form a smoothly continuous curved surface.

As described above, the first recess 170a, which is lower than the bottom surface of the stacked sheets, allows the user to grab the sheets from the front 301 side of the device and remove them from the discharge tray 170. The depth of the second recess 170c is also lower than the bottom surface of the stacked sheets. This allows the bottom and top surfaces of the stacked sheets to be grabbed in the second recess 170c. Therefore, even if the stacked sheets are long and large in the discharge direction 302, they can be easily removed. In other words, when removing a small number of large sheets, the user can insert their hands into either the first recess 170a or the second recess 170c to remove the sheets. Whether the user is standing on the upstream side of the discharge direction 302 or the downstream side of the discharge direction 302, the user can remove the sheets stacked on the discharge tray 170, which is highly convenient.

Here, when a large sheet that is long in the transport direction is stacked, especially when there are many of them, there is a concern that if an attempt is made to remove the sheet by grabbing only a portion of the edge of the sheet near the first recess 170a, the sheet may not be stable and may fall out of the hand. There is also a concern that the sheet may be damaged because it cannot be grasped stably, resulting in a decrease in the quality of the finished product. In this embodiment, the user can insert their fingers into both the first recess 170a and the second recess 170c to grasp the sheet, so that the stacked sheets can be stably removed even when many large sheets are stacked.

The second support portion 205 of the second region 202 is wide in the sheet width direction, so it can stably support the sheet. For example, it can prevent the sheet from falling due to poor stacking caused by the floating of the sheet due to charging during stacking. Charging during stacking occurs due to friction between the sheet and the conveying path when the discharge roller conveys the sheet. One type of stacking defect is that the stacked sheets repel each other due to charging of the sheets, causing the sheets to float. If the first recess 170a and the second recess 170c are present and the area supporting the sheet in the second region 202 is narrow in the width direction, the recess will not stably support the bottom surface of the floating sheet. Therefore, the sheet will fall from the recess to the front side of the main body, increasing the risk of poor stacking.

In this embodiment, the second support portion 205 of the second region 202 that supports the bottom surface of the sheet over a wide area in the sheet width direction is disposed between the first recess 170a and the second recess 170c in the discharge direction 302. Therefore, even if the sheet is floating, it is possible to prevent the sheet from falling toward the front of the main body.

These configurations make it easy to remove all sheet sizes from the smallest to the largest, and also realize a discharge tray that allows larger sheets to be removed with both hands. Furthermore, the stacking state of the sheets stacked on the discharge tray 170 is stable. In other words, this embodiment achieves both high sheet removal ease and stable stacking.

Figure 5 shows a modified example. The modified example in Figure 5 differs from the above embodiment in that it further includes a third recess 170e, and the other configurations are the same as those of the above embodiment. The third recess 170e is located closer to the center in the sheet width direction than the second recess 170c, and is arranged at the downstream end of the discharge tray 170 in the discharge direction 302. By having the third recess 170e downstream in the discharge direction 302 than the first recess 170a and the second recess 170c, it becomes possible to easily handle a wider range of sheet sizes. Instead of one third recess 170e, multiple third recesses 170e may be arranged in a row in the discharge direction 302. This makes it possible to handle long sheets and sheets that are not rectangular.

This embodiment provides the following advantages:

The first recess 170a of the discharge tray 170 extends from the upstream end of the discharge tray 170 in the discharge direction 302. The first recess 170a overlaps even the smallest sheet S2 in the width direction. Therefore, regardless of the size of the sheet in the width direction, a finger can be inserted into the first recess 170a to remove the sheet, which has the effect of improving the ease of removing the sheet.

The width D2 of the first recess 170a in the ejection direction 302 on the front 301 side of the device is larger than the width D1 on the rear side of the device. This makes it easier to reach into the first recess 170a.

Downstream of the first recess 170a is a second region 202 capable of supporting the entire width of the maximum size sheet S1. This prevents stacked sheets from collapsing toward the front of the device, resulting in poor stacking. Furthermore, downstream of the second region 202 in the discharge direction 302 is a second recess 170c, and in the sheet width direction, a portion of the maximum sheet S1 stacked on the discharge tray 170 overlaps with a portion or all of the second recess 170c. Therefore, even with a large sheet such as the maximum sheet S1, the stacked sheet can be grasped at two points, the first recess 170a and the second recess 170c, making it possible to grasp the sheet with both hands and remove it, resulting in high sheet removal properties.

Above the discharge tray 170, an upper discharge tray 172 and an image reading device 920 are arranged as upper members. Although the upper members make it difficult to see the sheets on the discharge tray 170 from above, the front side of the device of the discharge tray 170 is open. Here, the open end of the front side of the device of the discharge tray 170 can be removed by inserting a hand into the first recess 170a or the second recess 170c. Therefore, in this embodiment, even if an upper member such as the image reading device 920 is arranged, the sheets can be easily removed.

In the above embodiment, the first support portion 204, the second support portion 205, and the third support portion 206 are provided with ribs 402, but the support portions that support the seat may be without ribs.

Although the second recess 170c has an arc-shaped bottom, the bottom may be a flat surface that becomes lower as it approaches the front of the device.

Although the embodiment shows an example in which the discharge tray 170 is disposed below the image reading device (i.e., the internal discharge section 190, which is the space inside the body), the present invention is not limited to this. For example, the present invention can also be applied to an image forming device that does not have an image reading device or an upper discharge tray.

S sheet 100 image forming apparatus 161 discharge roller 170 discharge tray 170a first recess 170c second recess

Claims (8)

an image forming unit that forms an image on a sheet;
a discharge section that discharges a sheet formed by the image forming section;
a stacking section on which the sheets conveyed in the discharge direction and discharged by the discharge section are stacked,
The loading section is
a first region including a first support portion that supports the sheet and a first recess that is provided at one end in a sheet width direction perpendicular to the discharge direction and recessed downward;
a second region including a second support portion that supports a sheet and is wider than the width of a maximum size sheet in the sheet width direction, the second region being disposed downstream in the discharge direction from the first region and including an inclined surface portion at an end portion on the one side in the sheet width direction;
a third region including a third support portion that supports the sheet and a second recess that is provided at an end portion on the one side in the sheet width direction and recessed downward, the third region being disposed downstream of the second region in the discharge direction,
The inclined surface portion is inclined downward toward the one side in the sheet width direction,
the second recess includes a bottom portion that becomes lower toward the one side in the seat width direction,
a bottom portion of the second recess and the inclined surface portion are disposed so as to be continuous with each other in the discharge direction,
An image forming apparatus characterized in that, when the maximum size sheet is discharged to the stacking section by the discharge section and supported on the stacking section, when viewed from above, the maximum size sheet supported on the stacking section overlaps with the first recess and the maximum size sheet overlaps with the second recess, and the one end of the second support section in the sheet width direction is on the one side of the one end of the maximum size sheet in the sheet width direction. The image forming apparatus according to claim 1, characterized in that when the discharge section discharges a smallest sheet in the sheet width direction to the stacking section and supports the smallest sheet on the stacking section, the smallest sheet overlaps with the first recess when viewed from above. 3. The image forming apparatus according to claim 1 , wherein the bottom of the second recess includes a portion shaped like an arc. 4. The image forming apparatus according to claim 1, wherein the third area is provided at an end of the stacking section in the ejection direction . 5. The image forming apparatus according to claim 1 , wherein the first support portion is inclined upward as it goes downstream in the discharge direction. 6. The image forming apparatus according to claim 1 , further comprising an image reading device for reading an image of a document, the image reading device being disposed above the loading section. 7. The image forming apparatus according to claim 1, wherein the loading section has a rib that extends continuously across the first support section, the second support section, and the third support section. 8. The image forming apparatus according to claim 1, further comprising an operation unit that can be operated by a user from the one side in the sheet width direction.

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