Patent Application
20250115449
The present disclosure relates to a sheet stacking apparatus on which sheets are stacked, and an image forming apparatus including the sheet stacking apparatus.
Sheet stacking apparatuses (stackers) for discharging and stacking sheets having images formed thereon by an image forming apparatus and sheets to be processed after scanning images have heretofore been developed. In some sheet stacking apparatuses, conveyed sheets are stacked on wires.
Japanese Patent Application Laid-Open No. 2000-255875 discusses a technique in which a rib-shaped portion formed by bending a wire is provided so that various types of sheets can be favorably stacked regardless of the properties and sizes of the sheets to be used.
However, recent image forming apparatuses are required to support a wide variety of sheets and large sheets as compared to image forming apparatuses of related art. The recent sheet stacking apparatuses are also required to stack sheets having a large basis weight and large sheets as compared to sheet stacking apparatuses of related art. When sheets having a large basis weight or large sheets are stacked, the weight of sheets increases. If a stacking surface is formed of a cantilevered wire as in the related art, the wire cannot support the weight of stacked sheets. In other words, the wire itself can be deformed due to the weight of sheets, which may lead to deterioration in sheet stacking performance.
The present disclosure is directed to providing a sheet stacking apparatus with an improved sheet stacking performance.
According to some embodiments, a sheet stacking apparatus on which a sheet discharged by a discharge portion is stacked includes a wire including a first supported portion, a second supported portion, and a stacking portion on which the sheet discharged by the discharge portion is stacked and at least a part of which is located between the first supported portion and the second supported portion in a horizontal direction, a first support portion configured to support the first supported portion, and a second support portion configured to support the second supported portion.
Further features of the present disclosure will become apparent from the following description of exemplary embodiments with reference to the attached drawings.
Various exemplary embodiments, features, and aspects of the present disclosure will be described in detail below. Various technically desirable limitations are added in the exemplary embodiments to be described below. However, the scope of the present disclosure should not be unduly limited by the description of exemplary embodiments described below and the drawings. Not all of the configurations described in the exemplary embodiments are necessarily deemed to be essential.
A sheet stacking apparatus according to an exemplary embodiment of the present disclosure will be described below with reference to the drawings using an inkjet printing apparatus as an example of an image forming apparatus.
The inkjet printing apparatus 101 serving as an image forming apparatus to form an image on a sheet includes a sheet feed module 1000, a print module 2000, a drying module 3000, and a fixing module 4000. The inkjet printing apparatus 101 further includes a cooling module 5000, a reversing module 6000, and a sheet discharge/stacking module 7000. Cut sheets S supplied from the sheet feed module 1000 are conveyed along a conveyance path and are processed by each module. Then, the sheets S are discharged to the sheet discharge/stacking module 7000.
The sheet feed module 1000 has a configuration in which three containers 1100a to 1100c that store the sheets S are arranged and the containers 1100a to 1100c are each configured to be drawn to the front side of the inkjet printing apparatus 101. In each of the containers 1100a to 1100c, the sheets S are fed one by one by a separation belt 3001 and conveyance rollers, which serve as a sheet feed portion, and are conveyed to the print module 2000. The number of the containers is not limited to three. One or two containers, or four or more containers may be provided.
The print module 2000 includes a pre-image-formation registration correction portion (not illustrated), a print belt unit 2200, and a printing portion 2300 serving as an image forming portion. The inclination and position of each sheet S conveyed from the sheet feed module 1000 are corrected by the registration correction portion, and the sheet S is conveyed to the print belt unit 2200. The printing portion 2300 is located at a position opposed to the print belt unit 2200 with respect to the conveyance path. The printing portion 2300 is a sheet processing portion that performs a print process (printing) on the sheet S from above the conveyed sheet S using print heads to form an image on the sheet S. The print belt unit 2200 conveys the sheet S by suction, so that a clearance is secured between the sheet S and the print heads. The plurality of print heads is arranged along a conveyance direction. In the present exemplary embodiment, five line-type print heads corresponding to four ink colors of yellow (Y)), magenta (M), cyan (C), and black (Bk) and a reaction liquid are included. The number of colors and the number of print heads are not limited to five. As the inkjet printing method, a method using a heating element, a method using a piezoelectric element, a method using an electrostatic element, a method using a micro-electromechanical system (MEMS) element, and the like can be employed. Ink of each color is supplied to the corresponding print head via an ink tube from an ink tank (not illustrated). The sheet S printed by the printing portion 2300 is conveyed by the print belt unit 2200.
The drying module 3000 includes a decoupling portion 3200, a drying belt unit 3300, and a hot air blowing portion 3400. The drying module 3000 is a unit for reducing the liquid contained in the ink applied onto the sheet S by the printing portion 2300 in order to enhance the fixability of the ink to the sheet S. The sheet S printed by the printing portion 2300 in the print module 2000 is conveyed to the decoupling portion 3200 located within the drying module 3000. The decoupling portion 3200 conveys each sheet S by applying wind pressure from above and using friction with the belt. The decoupling portion 3200 conveys the sheet S while gently holding the sheet S on the belt, thereby preventing a deviation of the sheet S on the print belt unit 2200 to form an ink image. The sheet S conveyed from the decoupling portion 3200 is conveyed by suction by the drying belt unit 3300, and hot air is applied onto the sheet S from the hot air blowing portion 3400, which is located above the belt, to dry the ink applied surface of the sheet S.
The fixing module 4000 includes a fixing belt unit 4100. The fixing module 4000 causes the sheet S conveyed from the drying module 3000 to pass between heated upper and lower belt units, thereby allowing an ink solvent to be sufficiently absorbed in the sheet S.
The cooling module 5000 includes a plurality of cooling portions 5100. The cooling module 5000 is configured to cool the high-temperature sheet S conveyed from the fixing module 4000. Each cooling portion 5100 takes external air into a cooling box with a fan to increase the pressure within the cooling box, and applies air blown out from nozzles formed in a conveyance guide to the sheet S, thereby cooling the sheet S. The cooling portions 5100 are located on both sides of the conveyance path and are configured to cool each sheet S from the both sides thereof. A conveyance path switching portion is located within the cooling module 5000. The conveyance switching portion is configured to switch the conveyance path for the sheet S depending on whether the sheet S is conveyed to the reversing module 6000 or the sheet S is conveyed to a double-sided conveyance path to be used for double-sided printing. During double-sided printing, the sheet S is conveyed to the conveyance path located in the lower portion of the cooling module 5000. Then, the sheet S is further conveyed along the double-sided conveyance path of the fixing module 4000, the drying module 3000, the print module 2000, and the sheet feed module 1000. After that, the sheet S is conveyed again to the registration correction portion, the print belt unit 2200, and the printing portion 2300 in the print module 2000, and is printed by the printing portion 2300. A double-sided conveyance portion in the fixing module 4000 includes a reversing portion 4200 for reversing the front and back surfaces of the sheet S.
The reversing module 6000 includes a reversing portion 6400 and is configured to reverse the front and back surfaces of the sheet S to be conveyed, thereby making it possible to arbitrarily change the front and back sides of the sheet S to be discharged.
The sheet discharge/stacking module 7000 serving as a sheet stacking apparatus includes a top tray portion 7100 and a stacking tray portion 7200, which allow the sheets S conveyed from the reversing module 6000 to be aligned and stacked.
Next, a configuration example of the sheet discharge/stacking module 7000 will be described in detail.
When the sheet S is discharged from the reversing module 6000, the sheet S is conveyed into inlet rollers 701 and is conveyed through an inlet path 703. After that, according to a selection instruction from an operation portion (not illustrated) or the like, the conveyance path through which the sheet S is conveyed is switched by a first switch member 702, and then the sheet S is conveyed along the conveyance path.
If a user designates the top tray portion 7100 on the top surface of the sheet discharge/stacking module 700 as a sheet stacking position, the sheet S is guided to a first conveyance path 731 by the first switch member 702. The sheet S that has been guided to the first conveyance path 731 for conveying the sheet S upward is discharged onto the top tray portion 7100 by a discharge roller pair 730 serving as a discharge unit.
If the user designates the stacking tray portion 7200 as the sheet stacking position, the sheet S is guided to a second conveyance path 732 by the first switch member 702. After that, the sheet S is guided to sheet discharge rollers 707 via a second switch member 704, a third switch member 705, and a fourth switch member 706. The sheet S conveyed by the sheet discharge rollers 707 is further conveyed while being gripped by one of grippers 709a and 709b that are attached to a gripper belt 708.
The gripper belt 708 is suspended by a drive pulley 710 and a driven pulley 711, and is driven by a belt motor (not illustrated) to be rotated in a rotational direction 712 indicated by an arrow in
Further, a sheet discharge option (not illustrated) may be connected downstream of the sheet discharge/stacking module 7000. The conveyance path may be switched by any one of the second switch member 704, the third switch member 705, and the fourth switch member 706 depending on the sheet discharge height of the connected sheet discharge option, and the sheet S may be conveyed to the sheet discharge option.
The top tray portion 7100 includes a top cover 720 and wires 721. The wires 721 form a stacking surface on which each sheet S is to be stacked. In other words, each discharged sheet S is stacked on the wires 721.
The top cover 720 includes a horizontally extending flat surface portion 720c and an inclined portion 720a. The inclined portion 720a is surrounded by the flat surface portion 720c and is located below the flat surface portion 720c. The top cover 720 further includes a wall portion 720b that vertically extends toward the flat surface portion 720c from a lower end of the inclined portion 720a. The wall portion 720b is provided with a discharge port through which the sheet S to be discharged passes. The discharge roller pair 730 for discharging the sheet S faces the discharge port. The sheet S to be discharged by the discharge roller pair 730 through the discharge port of the wall portion 720b is discharged onto the wires 721. A lower portion of the wall portion 720b is provided with four first openings 723 at intervals in a sheet width direction.
As described in detail below, each of the wires 721 includes first bent portions 722a each including a vertex of the wire 721. A portion of each wire 721 that is located downstream of the first bent portions 722a in a sheet discharge direction and is located below the first bent portions 722a is supported by a support unit including the top cover 720. In other words, a lower portion of each wire 721 that faces downward via the first bent portions 722a is supported by the support unit. Even when the weight of the sheets S stacked on the stacking surface that is formed by the wires 721 is applied onto the wires 721, the wires 721 can support the weight of the sheets S, thereby preventing deformation of the stacking surface. Consequently, the sheets S can be stably stacked on the top tray portion 7100 in the sheet discharge/stacking module 7000.
The two second inclined portions 921 as a pair of portions extend vertically and are located at an interval in the sheet width direction perpendicular to the sheet discharge direction. The two second inclined portions 921 are connected to each other with a connecting portion 721b that is located below the second inclined portions 921. The connecting portion 721b includes a portion extending horizontally along the sheet width direction. Second bent portions 722b are located at both ends of the connecting portion 721b. The pair of second bent portions 722b is connected to the second inclined portions 921.
The wire 721 also includes third inclined portions 931 with a smaller inclination angle with respect to the horizontal direction than the first inclined portions 911. Third bent portions 722c are provided between the first inclined portions 911 and the third inclined portions 931.
As illustrated in
Each sheet S discharged from the discharge roller pair 730 is stacked on the wires 721. Specifically, the sheet S is supported by the first inclined portions 911 and the third inclined portions 931 of the wires 721 and the inclined portion 720a of the top cover 720. The first inclined portions 911 and the third inclined portions 931 serving as a stacking portion on which each sheet S is to be stacked are inclined upward toward the downstream side in the sheet discharge direction. Accordingly, the discharged sheet S is moved to the upstream side in the sheet discharge direction by its own weight along the inclination of the first inclined portions 911 and the third inclined portions 931. The movement of the sheet S toward the upstream side in the sheet discharge direction is stopped when the upstream-side edge of the sheet S is brought into contact with the wall portion 720b.
As illustrated in
A configuration example of a wire holding portion for holding the wires 721 on the upstream side of the first inclined portions 911 of the wires 721 in the sheet discharge direction will be described with reference to
As illustrated in
As described above with reference to
The present exemplary embodiment described above illustrates a configuration example in which the top cover 720 also functions as the support unit for supporting the wires 721. However, the wires 721 may be supported by a member other than the top cover 720. While the present exemplary embodiment described above illustrates a configuration example in which the positions of the wires 721 are regulated by the first openings 723 of the top cover 720, the wires 721 may be fitted into resin components or the like.
Next, a configuration example of a wire contact portion to be in contact with each wire 721 on the downstream side of the first inclined portions 911 of the wire 721 in the sheet discharge direction to support the wire 721 will be described with reference to
In the present exemplary embodiment, the top cover 720 is provided with a second opening 724. A support member 725 for regulating the position of the wire 721 is provided below the second opening 724. The support member 725 that constitutes the support unit for supporting the wire 721 together with the top cover 720 is fixed to a lower surface of the top cover 720. A horizontally extending upper surface of the support member 725 serving as a second support portion is in contact with the connecting portion 721b of the wire 721. In other words, the connecting portion 721b serving as a second supported portion of the wire 721 inserted into the second opening 724 is supported by the support member 725. The connecting portion 721b serving as the second supported portion is located at a position where at least parts of the first inclined portions 911 serving as the stacking portion are interposed between the connecting portion 721b and the third inclined portions 931 serving as a first supported portion in the horizontal direction. In the present exemplary embodiment, as viewed from above, at least parts of the first inclined portions 911 serving as the stacking portion are located between the third inclined portions 931 serving as the first supported portion and the connecting portion 721b serving as the second supported portion in the sheet discharge direction.
A part of the wire 721 is inserted into the second opening 724, thereby regulating the movement of the wire 721 such that the wire 721 can move only within the gap of the second opening 724 in the horizontal direction. In other words, the wire 721 is brought into contact with edges of the second opening 724, thereby regulating the movement of the wire 721 in a direction parallel to the sheet discharge direction. Furthermore, a downward movement of the wire 721 is regulated by the support member 725.
As illustrated in
In the present exemplary embodiment, the top cover 720, the support member 725, and the retaining member 726 are separate components. Alternatively, the top cover 720 and the support member 725 may be formed as a single member. The top cover 720 and the retaining member 726 may be formed as a single component. The retaining member 726 and the support member 725 may be formed as a single component. The top cover 720, the support member 725, and the retaining member 726 may be formed as a single member. The same advantageous effect can also be obtained by, for example, forming these members using a resin component, providing a shape into which the wire 721 can be fitted and bringing the wire 721 into contact with the members.
As illustrated in
The present exemplary embodiment described above illustrates a desirable configuration example in which the inclination angle (0) is set such that the second inclined portions 921 of the wire 721 are inclined downward toward the downstream side in the sheet discharge direction as illustrated in
Further, the portions between the vertices of the wire 721 and the supported portion located on the downstream side in the sheet discharge direction may be wires that are inclined upward toward the downstream side in the sheet discharge direction.
The present exemplary embodiment described above illustrates a configuration example in which the third inclined portions 931 of the wires 721 are supported by the inclined portion 720a of the top cover 720 and the sheets S are supported by the inclined portion 720a of the top cover 720 and the third inclined portions 931 of the wires 721. However, the inclined portion 720a of the top cover 720 need not necessarily be configured to support the sheets S. In this case, for example, the wall portion 720b of the top cover 720 may support the upstream side of the wires 721 in the sheet discharge direction.
For example, the sheets S may be supported by the inclined portion 720a of the top cover 720, and may not be supported by the third inclined portions 931 of the wires 721. In this case, the inclined portion 720a of the top cover 720 may be provided with grooves to which the third inclined portions 931 of the wires 721 are fitted.
While the present exemplary embodiment described above illustrates a configuration example in which the wires 721 are inserted into the second openings 724 of the top cover 720 and the wires 721 are supported by the support member 725 located below the second openings 724, the downstream side of the wires 721 in the sheet discharge direction may be supported by the upper surface of the top cover 720.
According to an exemplary embodiment of the present disclosure, it is possible to provide a sheet stacking apparatus with an improved sheet stacking performance.
While the present disclosure has been described with reference to exemplary embodiments, it is to be understood that the disclosure is not limited to the disclosed exemplary embodiments. The scope of the following claims is to be accorded the broadest interpretation so as to encompass all such modifications and equivalent structures and functions.
This application claims the benefit of priority from Japanese Patent Application No. 2023-174504, filed Oct. 6, 2023, which is hereby incorporated by reference herein in its entirety.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2023-174504 | Oct 2023 | JP | national |
