JP7551364B2 - SHEET SUPPORT DEVICE AND IMAGE FORMING APPARATUS - Google Patents

Description

The present invention relates to a sheet support device that supports a sheet and an image forming device that forms an image on a sheet supported by the sheet support device.

The sheet support device of the image forming device is provided with a side regulating plate that abuts against the sheet in the width direction perpendicular to the sheet transport direction and prevents the sheet transported to the image forming section from skewing. When a stack of sheets is set on a sheet support device having a side regulating plate, there is a risk that the side regulating plate will interfere with the stack of sheets, so a configuration has been disclosed in which the upper part of the side regulating plate is rotated to retract it (see Patent Document 1).

JP 2003-176037 A

However, in the sheet support device described in Patent Document 1, the user must rotate the upper part of the side regulating plate in advance, which reduces the ease of use when setting the sheet stack. Also, if the side regulating plate is configured to be movable, as in the sheet support device described in Patent Document 1, this leads to an increase in the number of parts, which may increase manufacturing costs.

The present invention aims to provide a seat support device that improves user operability while reducing manufacturing costs.

The present invention comprises a sheet supporting portion that supports a sheet, and a pair of regulating members having a regulating surface that abuts an end of a sheet stored in the sheet supporting portion in a width direction perpendicular to the sheet conveying direction, which are movable in the width direction relative to the sheet supporting portion, and which regulate the sheet stored in the sheet supporting portion inside the regulating surface, wherein at least one of the pair of regulating members has a recess that is recessed outward in the width direction more than the regulating surface and has an open upper end , and the regulating surface of at least one of the pair of regulating members includes an upstream portion that is upstream in the conveying direction more than the upstream end of the recess in the conveying direction, and a downstream portion that is downstream in the conveying direction more than the downstream end of the recess in the conveying direction , and the recess has a recessed shape that is recessed outward in the width direction formed by a curved surface .

The present invention improves user operability and reduces manufacturing costs.

1 is a schematic diagram of an image forming apparatus according to an embodiment of the present invention. FIG. 2 is a perspective view of a paper feed cassette according to the embodiment. FIG. 2 is a top view of the paper feed cassette according to the embodiment. FIG. 2 is a cross-sectional view of a paper feed cassette according to the embodiment. 1A is a diagram showing a state in which conveyance of a sheet stored in a sheet feed cassette according to the present embodiment is started, (b) is a diagram showing a state in which the trailing edge of the sheet whose conveyance has started passes through a recess, and (c) is a diagram showing a state in which the trailing edge of the sheet whose conveyance has started passes through an upstream regulating surface. 13A and 13B are diagrams illustrating a state in which a stack of sheets is accommodated in a conventional paper feed cassette having no recess in the side fence and a notch in a part of a regulating surface. 1A is a diagram showing a state in which the stack of sheets has started to be stored in the sheet feed cassette according to the embodiment, FIG. 1B is a diagram showing a state in which the stack of sheets is being stored in the sheet feed cassette by its own weight after the user releases the stack of sheets, and FIG. 1C is a diagram showing a state in which the stack of sheets has been completely stored in the sheet feed cassette. 5A and 5B are diagrams illustrating brightness levels of components constituting the paper feed cassette according to the embodiment.

Hereinafter, an embodiment of the present invention will be described in detail with reference to Figs. 1 to 8. First, the schematic configuration of the image forming apparatus of this embodiment will be described with reference to Fig. 1. Fig. 1 is a front view of an electrophotographic image forming apparatus 100.

[Image forming apparatus]
1, the image forming apparatus 100 includes an image reading unit 100A that reads image information of an original document, and an image forming unit 100B that forms an image on a sheet P as a recording material. The image forming apparatus 100 also includes a paper feeding unit 100C that supplies the sheet P to the image forming unit 100B.

The image reading unit 100A optically reads the image of the document placed on the document table 11 and converts it into optical information from the image information. The image forming device 100 modulates the recording light of the exposure device 4 of the image forming device 100B using the optical information converted by the image reading unit 100A. Note that the image forming device 100 may be configured to modulate the recording light of the exposure device 4 based on digital information as image information sent from an external computer.

The image forming unit 100B has a charging device 3 around the photosensitive drum 2, which is a photosensitive body, that uniformly charges the photosensitive drum 2. Also, an exposure device 4 is arranged around the photosensitive drum 2, which modulates and outputs recording light based on optical information read by the image reading unit 100A or digital information sent from an external computer, and scans the surface of the photosensitive drum 2 to form an electrostatic latent image. Also, around the photosensitive drum 2, a developing device 5 is arranged that supplies toner to the electrostatic latent image formed on the surface of the photosensitive drum 2 to visualize (develop) it and form a toner image, and a transfer unit 6 is arranged that transfers the toner image to a sheet P. Also, around the photosensitive drum 2, a cleaning device 7 is arranged that collects toner remaining on the photosensitive drum 2 after the toner image is transferred to the sheet P.

In parallel with the formation of a toner image on the photosensitive drum 2, a sheet P for image formation is transported from the paper feed section 100C. In the paper feed section 100C, two paper feed cassettes 20 (20a, 20b) are arranged on the upper side of the device body 101 of the image forming device 100 as sheet support devices for supporting the stored sheets P. In addition, in the paper feed section 100C, two rows of paper decks 40 (40a, 40b) that can stack a large volume of sheets P are arranged below the paper feed cassettes 20.

The sheets P supported by the paper feed cassette 20 and the paper deck 40 are transported one by one by the pickup roller 31 through the transport path 32 toward the registration roller pair 33, where skew is corrected. The registration roller pair 33 transports the sheet P to the transfer section 6 in accordance with the transfer timing of the toner image formed on the photosensitive drum 2, and causes the sheet P to carry the toner image.

The sheet P carrying the unfixed toner image is transported to the fixing device 9 by the transport belt 8, where it is sandwiched between a pair of rollers and heated and pressurized. When the toner melts and adheres to the sheet P and the image is fixed, the sheet P is discharged to a discharge tray (not shown) by a pair of discharge rollers 12 if an image is to be formed on one side of the sheet P. On the other hand, when images are to be formed on both sides of the sheet P, the sheet P that has passed through the fixing device 9 is transported again toward the pair of registration rollers 33 via the reverse transport path 34. Thereafter, an image is formed on the back side of the sheet P by a process similar to the process in which the image was formed on the front side, and the sheet P is discharged to a discharge tray to complete double-sided printing.

[Paper feed cassette configuration]
Next, the sheet support device and the sheet feed cassette 20 as a cassette of this embodiment will be described in detail with reference to Fig. 2 to Fig. 4. Fig. 2 is a perspective view of the sheet feed cassette 20, Fig. 3 is a top view of the sheet feed cassette 20, and Fig. 4 is a cross-sectional view taken along line A-A in Fig. 2 and Fig. 3. In this embodiment, the sheets P supported by the sheet feed cassette 20 are transported one by one in the transport direction B1 shown in Fig. 2 by the pickup roller 31 shown in Fig. 1.

As shown in FIG. 2, the paper feed cassette 20 is configured to be able to be pulled out toward the front side (in the direction of the arrow C in FIG. 2) of the device main body 101 (see FIG. 1) in which it is installed. The paper feed cassette 20 has plate-shaped side fences 21 and 22 as a pair of regulating members that abut the ends of the sheets P in the width direction B2 perpendicular to the conveying direction B1 on a base tray 30 as a sheet support section that supports the stored sheets P. The side fences 21 and 22 are each provided so as to be movable within a movable area Ar in the width direction B2. The paper feed cassette 20 also has a trailing edge regulating member 28 on the upstream side of the conveying direction B1 that regulates the trailing edge of the sheets P. The trailing edge regulating member 28 is provided so as to be movable in the conveying direction B1.

The side fence 21 has a restricting surface 23 that abuts against the end of the sheet P in the width direction B2, and restricts the position of the sheet P in the width direction B2 inside the restricting surface 23. The side fence 21 also has a first recess 25 that is recessed outward in the width direction B2 from the restricting surface 23 at the top in the vertical direction (opening side) and is positioned at the same position in the width direction B2 as the restricting surface 23 at the bottom in the vertical direction. In other words, the recess shape of the first recess 25 is a curved surface that bulges outward from the restricting surface 23 at the top in the vertical direction.

The regulating surface 23 includes a downstream regulating surface 23a as a downstream portion downstream in the conveying direction B1 of the downstream end 25a of the first recess 25. The regulating surface 23 also includes an upstream regulating surface 23b as an upstream portion upstream in the conveying direction B1 of the upstream end 25b of the first recess 25.

As shown in FIG. 4, the regulating surface 23 has a lower regulating surface 23c as a lower portion below the lower end 25c of the first recess 25 in the up-down direction. As shown in FIG. 2, the lower regulating surface 23c is provided near the upstream end and the downstream end of the side fence 21 in the conveying direction B1, and is formed in a straight line parallel to the conveying direction B1. The lower regulating surface 23c also has a notch 23d downstream of the center in the conveying direction B1.

The side fence 22 has a restricting surface 24 that abuts against the end of the sheet P in the width direction B2, and restricts the position of the sheet P in the width direction B2 inside the restricting surface 24. The side fence 22 also has a second recess 26 that is recessed outward in the width direction B2 from the restricting surface 24 at the top in the vertical direction (opening side) and is positioned at the same position in the width direction B2 as the restricting surface 24 at the bottom in the vertical direction. In other words, the recess shape of the second recess 26 is a curved shape that bulges outward from the restricting surface 24 at the top in the vertical direction.

The regulating surface 24 includes a downstream regulating surface 24a as a downstream portion downstream in the conveying direction B1 of the downstream end 26a of the second recess 26. The regulating surface 24 also includes an upstream regulating surface 24b as an upstream portion upstream in the conveying direction B1 of the upstream end 26b of the second recess 26.

As shown in FIG. 4, the regulating surface 24 has a lower regulating surface 24c as a lower portion below the lower end 26c of the second recess 26 in the vertical direction. As shown in FIG. 2, the lower regulating surface 24c is provided near the upstream end and downstream end of the side fence 22 in the conveying direction B1, and is formed in a straight line parallel to the conveying direction B1. The lower regulating surface 24c also has a notch 24d upstream of the center in the conveying direction B1.

As shown in FIG. 3, when a sheet P is stored in the paper feed cassette 20, the sheet P is stored so that its longitudinal direction is parallel to the transport direction B1. When a sheet P is stored in the paper feed cassette 20, the downstream end face of the sheet P in the transport direction B1 abuts against an inner wall 27 of the paper feed cassette 20 provided downstream in the transport direction B1. This inner wall 27 constitutes an abutment portion that abuts against the downstream end in the transport direction B1 of the sheet P stored in the base tray 30 in this embodiment.

The paper feed cassette 20 is configured so that the length from the inner wall 27 to the rear end regulating member 28 can be changed within a range of 279.4 to 431.8 mm by moving the rear end regulating member 28 in the conveying direction B1. This allows the paper feed cassette 20 to accommodate A3 size sheets with a longitudinal length of 420 mm and A4 size sheets with a longitudinal length of 297 mm. The paper feed cassette 20 is also configured so that it can accommodate legal size sheets with a longitudinal length of 355.6 mm and tabloid size sheets with a longitudinal length of 431.8 mm.

The shapes of the first recess 25 and the second recess 26 are described in detail below. Note that the specific numerical values for the dimensions of the side fences 21 and 22, the dimensions of the regulating surfaces 23 and 24, and the dimensions of the first recess 25 and the second recess 26 in the following description are merely examples used for the purpose of explanation, and the present invention is not limited thereto.

The side fences 21, 22 have a first recess 25 and a second recess 26 at positions where they overlap when viewed from the width direction B2. The center positions of the first recess 25 and the second recess 26 in the conveying direction B1 correspond to the longitudinal length of the sheets stored in the paper feed cassette 20.

When a sheet is stored in the paper feed cassette 20 so that its downstream end face in the transport direction B1 abuts against the inner wall 27, the center position of the longitudinal length of an A3 size sheet is 210 mm from the inner wall 27 (first position). When a sheet is stored in the paper feed cassette 20 so that its downstream end face in the transport direction B1 abuts against the inner wall 27, the center position of the longitudinal length of an A4 size sheet is 148.5 mm from the inner wall 27 (second position).

As a result, the center positions of the first recess 25 and the second recess 26 in the conveying direction B1 are 179 mm from the inner wall 27, which is approximately the center position between the first position and the second position. With this configuration, when storing A3 or A4 size sheets, the paper feed cassette 20 is lowered from the positions of the first recess 25 and the second recess 26, and does not interfere with the upper edges of the side fences 21 and 22, preventing damage to the stack of sheets.

In this embodiment, the side fences 21, 22 have a length of 240 mm in the conveying direction B1. In addition, in the paper feed cassette 20, the downstream regulating surfaces 23a, 24a and the upstream regulating surfaces 23b, 24b are brought into contact with at least 40% of the end surface of the A4 size sheet in the width direction B2, thereby effectively regulating the skew of the stored sheet P.

The first recess 25 in this embodiment has a length of 110 mm from the downstream end 25a to the upstream end 25b in the conveying direction B1. In other words, the side fence 21 has a downstream regulating surface 23a and an upstream regulating surface 23b that are 130 mm in total near the top end in the vertical direction where the first recess 25 bulges outward in the width direction B2 the most and the length of the downstream regulating surface 23a and the upstream regulating surface 23b is the shortest.

In addition, the second recess 26 in this embodiment has a length of 110 mm from the downstream end 26a to the upstream end 26b in the conveying direction B1. In other words, the side fence 22 has a downstream regulating surface 24a and an upstream regulating surface 24b that are 130 mm in total near the top end in the vertical direction where the second recess 26 bulges outward in the width direction B2 the most and the length of the downstream regulating surface 24a and the upstream regulating surface 24b is the shortest.

The dimension that is 40% of the longitudinal length of an A4 size sheet (297 mm) is 118.8 mm. Therefore, the side fences 21, 22 of the paper feed cassette 20 can regulate the position of the sheet P in the width direction B2 within a range of 40% or more, even when the sheet P is loaded up to the upper end of the side fences 21, 22 in the vertical direction, and skew can be sufficiently prevented.

The side fences 21 and 22 are configured to be located upstream of the center of the first recess 25 and the second recess 26 in the conveying direction B1. In other words, the side fences 21 and 22 are configured so that the downstream regulating surfaces 23a and 24a are longer in the conveying direction B1 than the upstream regulating surfaces 23b and 24b.

The first recess 25 and the second recess 26 are recessed 7 mm outward in the width direction B2 from the regulating surfaces 23 and 24, respectively. Therefore, when storing a stack of sheets in the paper feed cassette 20, even if the stack of sheets is stored offset from the center in the width direction B2, the recessed shapes of the first recess 25 and the second recess 26 guide the stack of sheets toward the center in the width direction B2.

In this embodiment, the side fences 21, 22 have a vertical height of 67 mm. When storing a stack of sheets in the paper feed cassette, if a stack of 500 sheets removed from a package is stored, the thickness of the stack of sheets will be 45 to 50 mm. For this reason, the first recess 25 and the second recess 26 have a vertical height of 45 mm so that when storing a stack of 500 sheets removed from a package, the stack of sheets can be accommodated on the lower restriction surfaces 23c, 24c after all of the sheets have been guided.

[Transportation of Sheets Stored in Paper Cassette]
Fig. 5A is a diagram showing a state in which conveyance of the sheet P stored in the sheet feed cassette 20 is started. Fig. 5B is a diagram showing a state in which the upstream end (rear end) of the sheet P, for which conveyance has started, passes through the first recess 25 and the second recess 26. Fig. 5C is a diagram showing a state in which the rear end of the sheet P, for which conveyance has started, passes through the downstream regulating surfaces 23a and 24a.

As shown in Figures 5(a) to (c), the side fences 21 and 22 have downstream regulating surfaces 23a and 24a located near the feed opening 50 through which the sheet P is transported, which are formed in a straight line parallel to the transport direction B1. In addition, the side fences 21 and 22 also have upstream regulating surfaces 23b and 24b on the upstream side of the transport direction B1, which are also formed in a straight line parallel to the transport direction B1.

The sheets P stacked in the paper feed cassette 20 are picked up one by one from the top sheet by the pickup roller 31 (see FIG. 1) and transported from the feed opening 50 toward the transport path 32 (see FIG. 1).

In the state where the conveyance of the sheet P is started as shown in FIG. 5(a), the movement of the sheet P in the width direction B2 is restricted by the downstream restricting surfaces 23a, 24a and the upstream restricting surfaces 23b, 24b of the side fences 21, 22. In the state where the rear end of the sheet P passes through the first recess 25 and the second recess 26 as shown in FIG. 5(b), the movement of the sheet P in the width direction B2 is restricted by the upstream restricting surfaces 23b, 24b of the side fences 21, 22. In the state where the rear end of the sheet P has passed through the first recess 25 and the second recess 26 as shown in FIG. 5(c), the movement of the sheet P in the width direction B2 is restricted by the upstream restricting surfaces 23b, 24b of the side fences 21, 22.

As described above, the first recess 25 and the second recess 26 have a shape that bulges outward from the regulating surfaces 23 and 24, respectively. Therefore, the end face in the width direction B2 of the sheet P stored in the paper feed cassette 20 is not regulated in the width direction B2 at the position facing the first recess 25 and the second recess 26.

The side fences 21 and 22 of this embodiment are configured to restrict the movement of the sheet P in the width direction B2 at two points, the downstream restriction surfaces 23a and 24a and the upstream restriction surfaces 23b and 24b, when the transport of the sheet P begins. With this configuration, the sheet feed cassette 20 of this embodiment can prevent the sheet P from skewing when the transport of the sheet P begins.

The side fences 21 and 22 have a first recess 25 and a second recess 26, which will be described in more detail later, so that the centers of the first recess 25 and the second recess 26 are located upstream of the center in the transport direction B1. In other words, the side fences 21 and 22 are configured so that the downstream regulating surfaces 23a and 24a are longer in the transport direction B1 than the upstream regulating surfaces 23b and 24b. In the paper feed cassette 20, when the rear end of the sheet P passes through the first recess 25 and the second recess 26, the pickup roller 31 is stably transporting the sheet P.

With this configuration, in the paper feed cassette 20, the downstream regulating surfaces 23a, 24a regulate the movement of the sheet P in the width direction B2 at one point during the transport of the sheet P, but the end faces of the sheet P in the width direction B2 abut against the downstream regulating surfaces 23a, 24a over a wide area. Therefore, the paper feed cassette 20 can sufficiently regulate the movement of the sheet P in the width direction B2 by the downstream regulating surfaces 23a, 24a, preventing the sheet P from skewing and realizing stable transport, thereby enabling the sheet P to be suitably fed to the image forming unit 100B (see FIG. 1). Furthermore, the paper feed cassette 20 can suppress the occurrence of paper feed jams by sufficiently preventing the sheet P from skewing.

[Loading sheets into the paper cassette]
6 is a diagram showing a state in which a stack of sheets is accommodated in a conventional sheet feed cassette 200 in which the side fence 210 does not have the first recess 25 and the second recess 26, and the regulating surface has a cutout portion 215. The stack of sheets shown in FIG. 6 is, for example, a stack of sheets taken out of a package of 500 sheets.

In general, when a stack of sheets is placed in a paper feed cassette, both ends of the stack in the longitudinal direction are grasped and the stack is lowered approximately vertically from above the paper feed cassette. In such a case, the stack of sheets bends downward at approximately the center in the longitudinal direction, so when the stack is placed in the paper feed cassette, it is placed from approximately the center in the longitudinal direction.

For this reason, when the sheet stack is stored in the sheet feed cassette 200 with the approximate center of the longitudinal direction of the sheet stack positioned away from the notch 215 provided in the side fence 210, the sheet stack interferes with the upper edge 210a of the side fence 210. When the sheet stack interferes with the upper edge 210a of the side fence 210, it causes problems when storing the sheet stack, and there is a risk that the sheets will be damaged, such as bent or dented.

Figure 7(a) shows the state in which the stack of sheets has started to be stored in the sheet feed cassette 20 of this embodiment, and Figure 7(b) shows the state in which the stack of sheets is being stored in the sheet feed cassette 20 by its own weight after the user has released the stack of sheets. And Figure 7(c) shows the state in which the stack of sheets has been completely stored in the sheet feed cassette 20.

As described above, in the paper feed cassette 20 of this embodiment, the downstream regulating surfaces 23a, 24a and the upstream regulating surfaces 23b, 24b provided at the top in the vertical direction among the regulating surfaces 23, 24 of the side fences 21, 22 are formed in straight lines parallel to the conveying direction B1. Furthermore, the paper feed cassette 20 stores the sheets P so that their longitudinal direction is parallel to the conveying direction B1. Therefore, the stack of sheets stored in the paper feed cassette 20 is also stored in the paper feed cassette 20 with the approximate center of the longitudinal direction bent downward.

In the first recess 25 formed in the side fence 21, the downstream end 25a in the conveying direction B1 is provided downstream of approximately the center of the side fence 21 in the conveying direction B1. In addition, in the first recess 25, the upstream end 25b in the conveying direction B1 is provided upstream of approximately the center of the side fence 21 in the conveying direction B1. In addition, the first recess 25 has a curved shape that bulges outward from the regulating surface 23.

In the second recess 26 formed in the side fence 22, the downstream end 26a in the conveying direction B1 is provided downstream of approximately the center of the side fence 22 in the conveying direction B1. In addition, in the second recess 26, the upstream end 26b in the conveying direction B1 is provided upstream of approximately the center of the side fence 22 in the conveying direction B1. In addition, the second recess 26 has a curved shape that bulges outward from the regulating surface 24.

With this configuration, in the paper feed cassette 20, as shown in FIG. 7(a), when the lower part of the approximate center of the sheet stack is lowered above the side fences 21, 22, the approximate center of the sheet stack is located near the first recess 25 and the second recess 26. Therefore, when storing a sheet stack in the paper feed cassette 20, the sheet stack can be lowered into the side fences 21, 22 without interfering with the side fences 21, 22.

As described above, the first recess 25 and the second recess 26 are shaped to bulge outward in the width direction B2 from the restricting surfaces 23 and 24 at the top in the vertical direction. The first recess 25 and the second recess 26 are shaped as curved surfaces whose positions in the width direction B2 change continuously so that the positions of the bottom ends 25c and 26c in the vertical direction are the same as the positions of the restricting surfaces 23 and 24 in the width direction B2.

Because of this configuration, when the user lets go of the stack of sheets in the paper feed cassette 20 and the stack falls under its own weight, as shown in FIG. 7(b), the stack is guided by the first recess 25 and the second recess 26 and is accommodated within the downward restriction surfaces 23c and 24c.

As described above, the lower regulating surfaces 23c, 24c formed below the side fences 21, 22 in the up-down direction are formed in a straight line parallel to the conveying direction B1 near the upstream end and downstream end of the conveying direction B1. The lower regulating surfaces 23c, 24c face each other at a distance substantially equal to the width of the sheet P in the width direction B2, and are configured to regulate the position of the end face of the sheet P in the width direction B2. In the sheet feed cassette 20, the downstream regulating surfaces 23a, 24a and the upstream regulating surfaces 23b, 24b regulate the position of the sheet in the width direction B2 for the sheet located above the lower regulating surfaces 23c, 24c in the sheet stack.

That is, in the paper feed cassette 20, as shown in FIG. 7(c), of the stack of sheets that have fallen under their own weight, the sheets below the first recess 25 and the second recess 26 are aligned parallel to the conveying direction B1 by the lower regulating surfaces 23c and 24c. Also, in the paper feed cassette 20, of the stack of sheets that have fallen under their own weight, the sheets facing the first recess 25 and the second recess 26 are aligned parallel to the conveying direction B1 by the downstream regulating surfaces 23a and 24a and the upstream regulating surfaces 23b and 24b.

With this configuration, the sheet feed cassette 20 of this embodiment can easily store the sheet stack without damaging the sheet stack when storing the sheet stack, improving the user's operability in storing the sheet stack in the correct position when transporting the sheets P to the image forming unit 100B (see FIG. 1). In addition, the sheet feed cassette 20 can improve the user's operability due to the simple shapes of the first recess 25 and the second recess 26 that bulge outward in the width direction B2 beyond the regulating surfaces 23, 24, and does not require additional parts to improve the user's operability, thereby reducing manufacturing costs.

[Paper Cassette Brightness]
Generally, the recording material used by the image forming apparatus 100 to form an image is a color with high brightness, such as white. Therefore, when a sheet stack is stored in the sheet feed cassette, the exposed surface that is exposed when the sheet feed cassette is pulled out from the device body is made of a color with lower brightness than the recording material, so that the user can easily distinguish between the sheet feed cassette and the sheet stack. In addition, by making the inside of the side fence a color with higher brightness than the exposed surface of the sheet feed cassette, the user can recognize that the sheet stack can be stored in the sheet feed cassette by lowering the sheet stack so that the low-brightness colored portion sandwiched between the side fences is not visible.

Figure 8 is a diagram showing the brightness of each part constituting the paper feed cassette 20 of this embodiment. In this embodiment, the inner surfaces and parts of the upper edges of the regulating surfaces 23 and 24 of the side fences 21 and 22, and the surfaces of the first recess 25 and the second recess 26 are colored white as a color of the first brightness. In addition, the exposed surface 60 of the paper feed cassette 20, which includes the base tray 30 and the rear end regulating member 28 that are exposed when the paper feed cassette 20 is pulled out from the device main body 101 (see Figure 1), is colored black as a color of the second brightness lower than the first brightness. In the base tray 30, the inner parts of the side fences 21 and 22 and the movable area Ar of the side fences 21 and 22 in the width direction B2 are also colored black as a color of the second brightness.

With this configuration, when the sheet cassette 20 of this embodiment stores sheet material, the difference in brightness between the black exposed surface 60 and the light-colored sheet material such as white becomes large, so that the user can easily visually identify the position of the sheet material. In addition, the inner and upper edges of the regulating surfaces 23 and 24, the first recess 25, and the second recess 26 of the sheet cassette 20 are configured in white, and the exposed surface 60 including the inside of the side fences 21 and 22 is configured in black. Therefore, the sheet cassette 20 can store the sheet material by lowering it from a position on the exposed surface 60 where the part inside the side fences 21 and 22 cannot be visually recognized, so that the user can easily store the sheet material.

As described above, in the paper feed cassette 20 of this embodiment, the sheet stack is stored in a position facing the first recess 25 and the second recess 26 that bulge outward from the regulating surfaces 23 and 24, preventing the sheet stack from interfering with the upper edges of the side fences 21 and 22. This allows the paper feed cassette 20 to prevent the sheet stack from interfering with the side fences 21 and 22 and being damaged when storing the sheet stack.

The sheet feed cassette 20 also guides the sheet stack by the first recess 25 and the second recess 26, which have a continuous curved shape that bulges outward in the width direction B2 at the top in the vertical direction and is at the same position as the regulating surfaces 23, 24 at the bottom in the vertical direction. This allows the sheet feed cassette 20 to improve the user's operability in storing the sheet stack, and to store the sheet stack in an appropriate position when transporting the sheets P to the image forming unit 100B (see FIG. 1). The sheet feed cassette 20 also improves the user's operability by the simple shape of the first recess 25 and the second recess 26, which bulge outward in the width direction B2 from the regulating surfaces 23, 24, and does not require additional parts to improve the user's operability, thereby reducing manufacturing costs.

[Modification]
In this embodiment, the paper feed cassette 20 has a first recess 25 in the side fence 21 and a second recess 26 in the side fence 22, but is not limited to this. It is sufficient that the paper feed cassette 20 has a recess in at least one of the side fences 21, 22 that bulges outward from the regulating surface in the width direction B2. It is preferable that the paper feed cassette 20 has a recess in the front side fence. Also, the paper feed cassette 20 may have a side fence that does not have a recess, and the entire inner surface of the side fence is composed of the regulating surface.

In addition, in this embodiment, the first recess 25 and the second recess 26 of the paper feed cassette 20 are configured with a curved recess shape, but this is not limited to this. The recess shape of the paper feed cassette 20 may also be configured with a flat inclined surface.

In addition, in this embodiment, the side fences 21 and 22 have lower regulating surfaces 23c and 24c below the first recess 25 and the second recess 26, but are not limited to this. The side fences 21 and 22 may be configured so that the lower ends 25c and 26c below the first recess 25 and the second recess 26 are connected to the base tray 30.

In addition, in this embodiment, the side fences 21, 22 are arranged so that the centers of the first recess 25 and the second recess 26 are located upstream of the centers of the regulating surfaces 23, 24 in the conveying direction B1, but this is not limited to this. The side fences 21, 22 may be arranged, for example, so that the centers of the first recess 25 and the second recess 26 are approximately the same as the centers of the regulating surfaces 23, 24.

In addition, in this embodiment, the side fences 21 and 22 have the first recess 25 and the second recess 26 at positions that overlap when viewed from the width direction B2, but this is not limited to this. For example, the side fences 21 and 22 may have the center of the first recess 25 and the center of the second recess 26 at different positions when viewed from the width direction B2.

In addition, in this embodiment, the surfaces of the regulating surfaces 23 and 24 and the surfaces of the first recess 25 and the second recess 26 of the paper feed cassette 20 are composed of a color of a first brightness, and the exposed surface 60 is composed of a color of a second brightness, but this is not limited to this. For example, the paper feed cassette 20 may have black characters written on a part of the surface of the regulating surfaces 23 and 24 colored white, and it is sufficient that the surfaces of the regulating surfaces 23 and 24 and the surfaces of the first recess 25 and the second recess 26 are composed of a color of a first brightness. In addition, the paper feed cassette 20 may have white characters or logos formed on a part of the exposed surface 60, and it is sufficient that the average brightness of the exposed surface 60 is composed of a color of a second brightness.

In addition, in this embodiment, the entire exposed surface 60 of the paper feed cassette 20 is made of the second brightness color, but this is not limited to this. For example, the paper feed cassette 20 may have a movable area Ar, which is an area in which the side fences 21 and 22 can move in the width direction B2, made of the second brightness color, and other parts made of a color of a brightness different from the second brightness color.

In addition, in this embodiment, the side fences 21 and 22 are made of plate-shaped members, but are not limited to this. The side fences 21 and 22 may be made of, for example, mesh-shaped members.

In addition, in this embodiment, the image forming apparatus 100 has a paper feed cassette 20 as a sheet support device, but is not limited to this. The image forming apparatus 100 may have, for example, a manual feed tray as a sheet support device, and a side fence provided on the manual feed tray may be configured to have a recess that bulges outward in the width direction from the regulating surface.

In this embodiment, the center positions of the first recess 25 and the second recess 26 in the conveying direction B1 are 179 mm from the inner wall 27 based on the center position of the longitudinal length of A3 and A4 size sheets, but are not limited to this. The center of the first recess 25 in the conveying direction B1 may be located within a range from 148.5 mm from the inner wall 27, which is the longitudinal center position of an A4 size sheet, to 210 mm from the inner wall 27, which is the longitudinal center position of an A3 size sheet. Similarly, the center of the second recess 26 in the conveying direction B1 may be located within a range of 148.5 to 210 mm from the inner wall 27.

20...Sheet support device, cassette (paper feed cassette): 21, 22...Regulating member (side fence): 23, 24...Regulating surface: 23a, 24a...Downstream portion (downstream regulating surface): 23b, 24b...Upstream portion (upstream regulating surface): 23c, 24c...Lower portion (lower regulating surface): 25, 26...Recess (first recess, second recess): 25a, 25b, 26a, 26b...End: 25c, 26c...Lower end: 30...Sheet support portion (base tray): 60...Exposed surface: 100...Image forming device: 100B...Image forming portion: 101...Device body: Ar...Moving area: B1...Transport direction: B2...Width direction: P...Sheet

Claims (9)

A seat support portion that supports the seat;
a pair of regulating members each having a regulating surface that abuts against an end of a sheet accommodated in the sheet support section in a width direction perpendicular to a sheet conveying direction, the regulating members being provided to be movable in the width direction relative to the sheet support section, and regulating the sheet accommodated in the sheet support section on the inside of the regulating surface;
At least one of the pair of regulating members has a recess that is recessed outward in the width direction from the regulating surface and has an open upper end ,
the regulating surface of at least one of the pair of regulating members includes an upstream portion that is located upstream in the transport direction of an upstream end of the recess in the transport direction, and a downstream portion that is located downstream in the transport direction of a downstream end of the recess in the transport direction ,
The recess has a curved shape recessed outward in the width direction.
A seat support device comprising: At least one of the regulating surfaces of the pair of regulating members includes a lower portion that is lower than a lower end of the recess in the up-down direction.
2. The seat support device according to claim 1 . At least one of the pair of regulating members is disposed such that a center of the recess is located upstream of a center of the regulating surface in the transport direction.
3. The seat support device according to claim 1 or 2 . Each of the pair of regulating members has the recess at a position where the recess overlaps when viewed from the width direction.
4. The seat support device according to claim 1, wherein the seat support device is a seat supporting device. the pair of regulating members have an average brightness of a surface of the regulating surface and a surface of the recessed portion that is a first brightness;
the sheet support portion has a movable region, which is a region in which the pair of regulating members move in the width direction, and the movable region has an average brightness of a second brightness that is lower than the first brightness.
5. The seat support device according to claim 1, wherein the seat support device is a seat supporting device. a cassette for accommodating a sheet in the sheet support portion;
the cassette is provided in a device body so as to be removable from the device body for transporting the stored sheets;
the cassette has an exposed surface that is exposed upward when the cassette is pulled out from the apparatus body,
the exposed surface has an average brightness of the second brightness;
6. The seat support device according to claim 5 . a contact portion that contacts an end portion of the sheet accommodated in the sheet support portion on a downstream side in the conveying direction,
The recess has a center located within a range of 148.5 to 210 mm from the contact portion in the conveying direction.
7. The seat support device according to claim 1, wherein the seat support device is a seat supporting device. A seat support portion that supports the seat;
a pair of regulating members each having a regulating surface that abuts against an end of a sheet accommodated in the sheet support section in a width direction perpendicular to a sheet conveying direction, the regulating members being provided to be movable in the width direction relative to the sheet support section, and regulating the sheet accommodated in the sheet support section on the inside of the regulating surface;
At least one of the pair of regulating members has a recess that is recessed outward in the width direction from the regulating surface and has an open upper end,
the regulating surface of at least one of the pair of regulating members includes an upstream portion that is located upstream in the transport direction of an upstream end of the recess in the transport direction, and a downstream portion that is located downstream in the transport direction of a downstream end of the recess in the transport direction,
At least one of the pair of regulating members is disposed such that a center of the recess is located upstream of a center of the regulating surface in the transport direction.
A seat support device comprising : A seat support device according to any one of claims 1 to 8,
an image forming unit that forms an image on the sheet fed from the sheet supporting device,
1. An image forming apparatus comprising:

Images