Medium supply device

Abstract

The invention provides a medium supply device. In a medium supply device provided with a pressing member for pressing an upstream side end portion of a floating uppermost layer medium downward in a conveying direction, floating failures and conveying failures are prevented. The pressing member (60) presses downward the upstream-side end in the transport direction (D) of the uppermost medium (M) that floats up by the floating air (A1) blown out by the floating air blowing mechanism (21). The pressing force adjustment mechanism (70) increases the pressing force (F1, F2) (F2 > F1) by the pressing member (60) when the end shield (50) is located at a second position (P2) upstream of the first position (P1) in the transport direction (D) in conjunction with the movement of the end shield (50) in the transport direction (D) compared with when the end shield (50) is located at the first position (P1).

Description

TECHNICAL FIELD

[0001] The present application relates to a medium feeding device that has a pressing member that presses the upstream side end portion of a medium in the conveyance direction toward the lower side. BACKGROUND

[0002] In the past, a sheet feeding device has been known that has an end guard that restricts the position of the upstream end of a sheet on a sheet feeding table (see, for example, Patent Literature 1).

[0003] Further, in order to improve the operability at the time of sheet loading, a sheet feeding device has been proposed that has an end portion pressing member that presses the upper surface of the end portion of a sheet and a release mechanism that releases the locking of the end portion pressing member and moves the end portion pressing member to a position above the upper surface of the end portion of the sheet (see, for example, Patent Literature 2).

[0004] Prior art documents

[0005] Patent documents

[0006] Patent Literature 1: Japanese Patent Application Publication No. 2021-031238

[0007] Patent Literature 2: Japanese Patent Application Publication No. 2008-094594 SUMMARY

[0008] PROBLEMS TO BE SOLVED BY THE INVENTION

[0009] Further, in a medium feeding device that adsorbs a medium such as a sheet that has floated up due to the blowing of the floating air to the conveyance mechanism by sucking the air, by pressing the upstream side end portion of the medium in the conveyance direction toward the lower side by the pressing member, it is possible to prevent the overlapping feeding of the second and subsequent media together with the uppermost layer of the medium.

[0010] For a medium that is relatively short in the conveyance direction, the conveyance mechanism and the pressing member are close. Therefore, if the pressing member presses the upstream side end portion of the medium toward the lower side with a strong force, floating failure in which the medium is not lifted up by the floating air or is adsorbed to the conveyance mechanism or the like in a state in which the upstream side of the medium is greatly sagging downward occurs. If such floating failure occurs, empty feeding in which the uppermost layer of the medium is not conveyed as intended occurs.

[0011] Next, for a medium having a relatively long length in the conveyance direction, the guiding by the side guard becomes insufficient as the length of the medium on the upstream side of the conveyance direction from the side guard becomes longer, and the skew of the floated medium is likely to occur. However, if the pressing force of the pressing member is weakened in coordination with a medium having a relatively short length in the conveyance direction, the skew of the medium cannot be prevented, and conveyance failure such as the occurrence of a shift (a skew-induced shift, a misalignment in the width direction) in the medium and the image formation content after the medium is fed occurs.

[0012] An object of the present application is to prevent float failure and conveyance failure in a medium feeding apparatus provided with a pressing member that presses a conveyance direction upstream end portion of a floated uppermost layer medium downward.

[0013] Solution to the problem

[0014] In one aspect, a medium feeding apparatus includes a loading table that loads a plurality of media; a float air blowing mechanism that blows float air that causes at least an uppermost layer medium of the plurality of media loaded on the loading table to float; a conveyance mechanism that conveys the uppermost layer medium in a conveyance direction; a suction mechanism that causes the uppermost layer medium to be adsorbed to the conveyance mechanism by suction air; an end guard that is configured to be movable in the conveyance direction, and that limits a position of an upstream end portion of the plurality of media in the conveyance direction; a pressing member that presses the upstream end portion of the uppermost layer medium downward; and a pressing force adjustment mechanism that, in conjunction with movement of the end guard in the conveyance direction, enhances a pressing force with which the pressing member presses the upstream end portion of the uppermost layer medium downward when the end guard is in a second position compared to when the end guard is in a first position, the second position being on an upstream side of the first position in the conveyance direction.

[0015] Effects of the invention

[0016] According to the aspect, in a medium feeding apparatus provided with a pressing member that presses a conveyance direction upstream end portion of a floated uppermost layer medium downward, float failure and conveyance failure can be prevented. BRIEF DESCRIPTION OF DRAWINGS

[0017] Figure 1 is a front view showing an image forming system provided with a medium feeding apparatus of one embodiment.

[0018] Figure 2 is a plan view showing an end guard, a side guard, and the like of one embodiment.

[0019] Figure 3 is a view showing a control structure of a medium feeding apparatus of one embodiment.

[0020] Figure 4A Fig. 2 is a plan view showing a pressing member, a pressing force adjusting mechanism, etc. at the time of loading of a small-sized medium according to an embodiment.

[0021] Figure 4B Fig. 3 is a front view showing a pressing member, a pressing force adjusting mechanism, etc. at the time of loading of a small-sized medium according to an embodiment.

[0022] Figure 5A Fig. 4 is a plan view showing a pressing member, a pressing force adjusting mechanism, etc. at the time of loading of a large-sized medium according to an embodiment.

[0023] Figure 5B Fig. 5 is a front view showing a pressing member, a pressing force adjusting mechanism, etc. at the time of loading of a large-sized medium according to an embodiment.

[0024] Figure 6 Fig. 6 is a front view of a medium feeding device showing a relationship of a pressing force at the time of loading of a small-sized medium according to an embodiment.

[0025] Figure 7 Fig. 7 is a front view of a medium feeding device showing a relationship of a pressing force at the time of loading of a large-sized medium according to an embodiment.

[0026] Figure 8 Fig. 8 is a plan view showing a representation end plate, a side plate, etc. for explaining a diagonal movement of a large-sized medium according to an embodiment.

[0027] BRIEF DESCRIPTION OF THE DRAWINGS

[0028] 1, medium supply device; 10, loading table; 21, floating air blowing mechanism; 22, separation air blowing mechanism; 30, conveying mechanism; 31, conveying belt; 32, 33, pulley; 40, suction mechanism; 50, end guard; 51, guard main body; 51a, curved portion; 51b, swing shaft; 51c, protrusion; 52, guard guide portion; 52a, support plate; 52b, 52c, fixing screw; 52d, circular arc hole; 52e, gear hole; 52f, standing portion; 53, guard shaft; 53a, D-shaped cut portion; 54, guide shaft; 54a, D-shaped cut portion; 54b, slide pin; 55, medium guide member; 55a, long hole; 60, pressing member; 70, pressing force adjustment mechanism; 71, elastic body; 72, support member; 73, sector gear (linkage member); 81, 82, side guard; 91, control portion; 92, storage portion; 93, interface portion; 94, loading table driving portion; 95, conveying mechanism driving portion; 100, image forming system; 101, image forming apparatus; 110, image forming portion; 120, conveying portion; 130, registration roller pair; Al, floating air; A2, separation air; A3, suction air; D, conveying direction; Fl, F2, pressing force; F10, suction force; F20, floating force; H, shaft holding portion; M, medium; Ml, small-size medium; M2, large-size medium; M2S, obliquely running large-size medium; Pl, first position; P2, second position. DETAILED DESCRIPTION

[0029] Hereinafter, a medium supply device of an embodiment of the present application will be described with reference to the drawings.

[0030] Figure 1 is a front view showing an image forming system 100 provided with a medium supply device 1 of an embodiment.

[0031] Figure 2 is a plan view showing an end guard 50, side guards 81, 82, and the like.

[0032] Figure 3 is a view showing a control structure of the medium supply device 1.

[0033] In addition, with respect to each direction of up and down, front and back, and left and right shown in Figure 1 and Figure 2 and the following Figures 4A to 8 , the up and down direction is a vertical direction, and the front and back direction and the left and right direction are horizontal directions. The above-described directions are one example in a case where the conveying direction D is set as the right direction.

[0034] Figure 1The media supply device 1 shown supplies media M to the image forming unit 110 of the image forming apparatus 101. The media supply device 1 and the image forming apparatus 101 can be configured independently of each other as part of the image forming system 100, or the media supply device 1 can be configured as part of the image forming apparatus 101. When the media supply device 1 is configured as part of the image forming apparatus 101, the image forming apparatus 101 can also be considered as the image forming system 100. Furthermore, the object to which the media M is supplied by the media supply device 1 is not limited to the image forming apparatus 101, but can also be other devices such as a transport device, a processing device (e.g., an inspection device, a post-processing device after image formation), etc. Moreover, the medium M can be, for example, paper, but can also be other media such as film, envelopes, etc. Furthermore, multiple media supply devices 1 can be arranged vertically, for example, supplying media M to a single device (e.g., the image forming apparatus 101).

[0035] like Figure 1 As shown, the medium supply device 1 includes a loading platform 10, a floating air blowing mechanism 21, a separating air blowing mechanism 22, a conveying mechanism 30, a suction mechanism 40, an end guard plate 50, a pressing member 60, and a pressing pressure adjustment mechanism 70. Furthermore, as... Figure 2 As shown, the medium supply device 1 also includes a pair of side guard plates 81, 82 and a shaft retaining part H. Furthermore, as... Figure 3 As shown, the media supply device 1 also includes a control unit 91, a storage unit 92, an interface unit 93, a loading platform drive unit 94, and a conveying mechanism drive unit 95.

[0036] exist Figure 1 The loading platform 10 shown loads multiple media (M). The loading platform 10 passes through... Figure 3 The loading platform drive unit 94 shown is raised and lowered by driving. For example, Figure 3 When the control unit 91, as shown, detects a decrease in the remaining amount of medium M based on the detection results of a loading surface detection sensor (not shown) and a floating state detection sensor, it controls the loading platform drive unit 94 to raise the loading platform 10 by the amount of the decrease in medium M. Thus, without expelling the floating air A1, the height of the uppermost medium M among the multiple mediums M loaded on the loading platform 10 is maintained at a predetermined loading surface height.

[0037] The floating air blowing mechanism 21 blows floating air Al that floats at least the uppermost sheet M of the plurality of sheets M loaded on the loading table 10. For example, the floating air blowing mechanism 21 is disposed at a position on the downstream side of the plurality of sheets M in the conveyance direction D with respect to the loading table 10, and blows the floating air Al for floating the plurality of sheets M (10 sheets or so as one example) including the uppermost sheet M from a duct by the operation of a fan. Note that the floating air blowing mechanism 21 is not limited to be disposed at a position on the downstream side of the plurality of sheets M in the conveyance direction D with respect to the loading table 10, and can be disposed on both sides in the width direction (front-rear direction) of the sheets M.

[0038] The separation air blowing mechanism 22 blows separation air A2 for separating the uppermost sheet M and the second sheet M from the lower part of the uppermost sheet M. For example, the separation air blowing mechanism 22 is disposed at a position on the downstream side of the plurality of sheets M in the conveyance direction D with respect to the loading table 10, and blows the separation air A2 from a duct by the operation of a fan. Note that the separation air blowing mechanism 22 is not limited to be disposed at a position on the downstream side of the plurality of sheets M in the conveyance direction D with respect to the loading table 10, and can be disposed on both sides in the width direction (front-rear direction) of the sheets M.

[0039] The conveyance mechanism 30 has a conveyance belt 31 and pulleys 32, 33 on which the conveyance belt 31 is stretched. One of the pulleys 32, 33 is a driving pulley, and the other is a driven pulley. The driving pulley of the pulleys 32, 33 is rotated by the driving of the conveyance mechanism driving section 95 shown in Fig. 1, and rotates the conveyance belt 31. Thus, the conveyance mechanism 30 conveys the uppermost sheet M of the plurality of sheets M loaded on the loading table 10 to the right in Fig. 1 in the conveyance direction D, and hands over to the registration roller pair 130 of the image forming apparatus 101. Figure 3 Figure 1

[0040] The conveyance belt 31 is provided with a plurality of through holes not shown, through which the air to be described later, that is, the suction air A3 is passed. Note that the conveyance mechanism 30 as a conveyance member for conveying the sheets M can have other conveyance members such as a roller conveyer instead of the conveyance belt 31, but since the conveyance belt 31 can adsorb and convey the sheets M in surface contact with the sheets M, it is preferable that the conveyance mechanism 30 has the conveyance belt 31 as a conveyance member.

[0041] ​​The suction mechanism 40 is provided, for example, in an area surrounded by the conveying belt 31 of the conveying mechanism 30. The suction mechanism 40 sucks the suction air A3 from a suction source (not shown) such as a suction fan via a duct and through a plurality of through-holes provided in the conveying belt 31, thereby causing the uppermost medium M among the plurality of media M loaded on the loading table 10 to be sucked to the conveying mechanism 30.

[0042] The end guard 50 is configured to be movable in the conveying direction D, and restricts the position of the upstream side end portion of the plurality of media M in the conveying direction D. As shown in FIG. 1, the end guard 50 has a guard main body 51, a guard guide 52, a guard shaft 53, a guide shaft 54, and a medium guide member 55. Figures 4A to 5B

[0043] Although one example, the guard main body 51 includes a plate-shaped portion extending frontward and rearward, leftward and rightward, two plate-shaped portions bent downward from both the front and rear ends of the plate-shaped portion and extending upward and downward and leftward and rightward, and a portion bent downward from the right end (downstream side end portion in the conveying direction D) of the plate-shaped portion extending frontward and rearward and leftward and rightward, and in the portion bent downward, the guard main body 51 is in contact with the upstream side end portion of the medium M. A bent portion 51a is provided at the lower end of the contact portion, and the bent portion 51a is obliquely bent in such a manner as to move away from the upstream side in the conveying direction D from the medium M.

[0044] Further, the guard main body 51 is provided with a swing shaft 51b that supports the medium guide member 55 to be swingable, and a protrusion 51c that is inserted into a long hole 55a of the medium guide member 55.

[0045] The guard guide 52 guides the movement of the guard main body 51 in the conveying direction D to be horizontal together with the guard shaft 53 and the guide shaft 54 described later. The guard guide 52 includes a support plate 52a, fixing screws 52b, 52c, a circular arc hole 52d, a gear hole 52e, and a standing portion 52f.

[0046] Although one example, the support plate 52a is formed in a letter L-shaped plate by a plate-shaped portion extending frontward and rearward and leftward and rightward, and a plate-shaped portion bent downward from the front end of the plate-shaped portion and extending upward and downward and leftward and rightward.

[0047] One of the fixing screws 52b is fixed to the vicinity of one end (front end) of the guard shaft 53 in the portion of the support plate 52a extending frontward and rearward and leftward and rightward. The other of the fixing screws 52c is fixed to the vicinity of one end (front end) of the guide shaft 54 in the portion of the support plate 52a extending frontward and rearward and leftward and rightward.

[0048] The circular arc hole 52d is provided in the portion of the support plate 52a extending frontward and rearward and leftward and rightward in a circular arc shape, and guides the sliding pin 54b provided at one end of the guide shaft 54 described later.

[0049] ​The gear hole 52e is a hole portion for arranging the sector gear 73 of the pressing force adjustment mechanism 70 described later in a portion of the support plate 52a that expands to the right and left and front and rear.

[0050] The standing portion 52f stands at a boundary portion of the support plate 52a from the cover plate main body 51 and supports the sector gear 73 so as to be rotatable.

[0051] The cover plate shaft 53 is fixed to the support plate 52a at one end thereof by the fixing screw 52b as described above and is held by the shaft holding portion H at the other end (rear end) thereof. The shaft holding portion H is fixed to a housing (exterior frame) of the medium supply device 1, for example, but can be fixed to a housing of the image forming apparatus 101 in the following manner or the like.

[0052] The guide shaft 54 is arranged in parallel with the cover plate shaft 53 and is fixed to the support plate 52a at one end thereof by the fixing screw 52c as described above and is held by the shaft holding portion H at the other end (rear end) thereof.

[0053] Therefore, the cover plate shaft 53 and the guide shaft 54 rotate in conjunction with the movement of the cover plate main body 51 in the conveyance direction D. In addition, D-shaped cut portions 53a, 54a that come into contact with the bottom surface of the support plate 52a are provided at the upper portions of the one end (front end) sides of the cover plate shaft 53 and the guide shaft 54.

[0054] The medium guide member 55 is in the shape of a sector plate and guides the medium M that protrudes to the upstream side in the conveyance direction D when the loading table 10 is raised to an appropriate position. The medium guide member 55 is supported so as to be swingable by the swing shaft 51b of the cover plate main body 51 described above. In addition, an arc-shaped long hole 55a is provided in the medium guide member 55. The medium guide member 55 is supported to the cover plate main body 51 by the insertion of the protrusion 51c of the cover plate main body 51 into the long hole 55a. The medium guide member 55 is urged in the clockwise direction in FIG. 8 by a torsion spring, and when the lower end of the medium guide member 55 comes into contact with the loading table 10, the medium guide member 55 is raised while rotating (swinging) in the counterclockwise direction against the urging force of the torsion spring. Figure 4B

[0055] The pressing member 60 presses the upstream side end portion in the conveyance direction D of the uppermost layer medium M loaded on the loading table 10 downward. As shown in FIGS. 9 and 10, the pressing member 60 is in the shape of a letter L, for example, when viewed from the front, and comes into contact with the upper surface of the upstream side end portion of the medium M at the bottom surface. The pressing member 60 can also be referred to as a press block, a press plate, a push rod, or the like. In addition, the upstream side end portion in the conveyance direction D of the medium M that is pressed by the pressing member 60 can be a position at which the periphery of the medium M is spaced apart from the upstream side in the conveyance direction D. Furthermore, the bottom surface of the pressing member 60 can be located at a position lower than the bottom surface of the conveyance mechanism 30 (the medium M suction surface). Figure 4B Figure 5B ​​​

[0056] The pressing force adjustment mechanism 70 adjusts the pressing force Fl, F2 with which the pressing member 60 presses the upstream side end portion of the uppermost layer of the media M downward in association with the movement of the end guard plate 50 in the conveyance direction D. When the end guard plate 50 is in the first position Pl (refer to Figure 4A and Figure 4B ), the pressing force adjustment mechanism 70 enhances the pressing force Fl, F2 with which the pressing member 60 presses the upstream side end portion of the uppermost layer of the media M downward in comparison with when the end guard plate 50 is in the first position Pl (refer to Figure 5A and Figure 5B ). In addition, the first position Pl of the end guard plate 50 is a position when the upstream side end portion of the small size media Ml, which is relatively short in the conveyance direction D of the media M, is restricted. Further, the second position P2 of the end guard plate 50 is a position when the upstream side end portion of the large size media M2, which is relatively long in the conveyance direction D of the media M, is restricted. Here, the small size media Ml is, for example, A4 paper loaded with the short side parallel to the conveyance direction D, and the large size media M2 is, for example, A3 paper loaded with the long side parallel to the conveyance direction D. In addition, as the small size media Ml and the large size media M2, media M of the same size with different orientations at the time of loading can also be used.

[0057] The pressing force adjustment mechanism 70 has an elastic body 71, a support member 72, and a sector gear 73 as one example of a linkage member.

[0058] The elastic body 71 presses the pressing member 60 downward. The elastic body 71 is, for example, a compression coil spring extending in the vertical direction and having a lower end coupled to the pressing member 60. As the elastic body 71, other springs, rubber, or the like can also be used in addition to the compression coil spring.

[0059] The support member 72 is coupled to an upper end of the elastic body 71 and supports the elastic body 71 at the upper end. The support member 72 has teeth that engage with the sector gear 73 and is raised and lowered in association with the rotation of the sector gear 73. The support member 72 can also be referred to as a pressure variable member, a raising and lowering member, or the like. In addition, a hole through which an upper portion of the pressing member 60 passes can be provided in the support member 72.

[0060] When the end guard plate 50 moves in the conveyance direction D, the guard plate shaft 53 rotates clockwise in Figure 4A , and in association therewith, the sector gear 73 is pressed by the front end of the guard plate shaft 53 in the conveyance direction D and rotates counterclockwise in Figure 4B , causing the support member 72 to rise. Further, when the end guard plate 50 moves in the opposite direction of the conveyance direction D, the guard plate shaft 53 rotates counterclockwise in Figure 5AWhen rotated clockwise, the sector gear 73 is not pressed by the front end of the guard plate shaft 53, for example, under the elastic force of the torsion spring. Figure 5B The clockwise rotation of the support member 72 causes it to descend. Alternatively, if the front end of the guard plate shaft 53 is connected to the sector gear 73, the torsion spring can be omitted.

[0061] Figure 2 The side guards 81 and 82 shown restrict the position of the end of the medium M in the width direction (front-to-back direction) orthogonal to the conveying direction D. The side guards 81 and 82 can be configured to move along the width direction in accordance with the dimensions of the medium M. Furthermore, in Figure 1 The illustrations of side guards 81 and 82 are omitted in the text.

[0062] Figure 3 The control unit 91 shown has a processor (e.g., CPU: Central Processing Unit) that functions as an arithmetic processing unit controlling the operation of the media supply device 1 as a whole. It executes a predetermined program, for example, by reading it from the storage unit 92 or from a storage medium (a non-transitory computer-readable storage medium) that can be attached to or detached from the media supply device 1. The control unit 91 controls the operation of each part of the media supply device 1 by executing this program. Furthermore, in cases where the media supply device 1 is integrally mounted on the image forming apparatus 101, the control unit of the image forming apparatus 101 can also be used as the control unit 91 of the media supply device 1.

[0063] Storage unit 92 may include, for example, a read-only semiconductor memory (ROM) pre-stored with a predetermined control program, or a semiconductor memory (RAM) that can be read and written at any time as needed when the processor executes various control programs.

[0064] The interface unit 93 exchanges and receives various types of information with external devices such as the image forming apparatus 101. For example, the interface unit 93 receives information such as the supply request and supply stop request of the medium M from the control unit of the image forming apparatus 101, and the control unit 91 controls the operation of each part of the medium supply device 1 based on the above information.

[0065] The loading platform drive unit 94 has an actuator such as a motor that raises and lowers the loading platform 10.

[0066] The conveying mechanism drive unit 95 has an actuator such as a motor, which causes one of the pulleys 32 and 33 of the conveying mechanism 30 to rotate as a drive pulley.

[0067] Next, regarding Figure 1 The image forming apparatus 101 shown will be described.

[0068] The image forming apparatus 101 is provided with an image forming section 110, a conveying section 120, and a positioning roller pair 130. In addition, in the Figure 1 conveying mechanism 30 of the medium supply apparatus 1 to the image forming section 110 of the image forming apparatus 101 is indicated by a single-dot chain line. In this conveying path, the medium M can be guided by an upper and lower pair of plate-shaped conveying guides, not shown.

[0069] The image forming section 110 has, for example, a linear inkjet head, not shown, of each color used for image formation. The image forming method of the image forming section 110 can also be any image forming method other than the inkjet method.

[0070] The conveying section 120 is disposed in opposition to the image forming section 110. The conveying section 120 conveys the medium M using a conveying belt, for example, while the medium M is being sucked.

[0071] The positioning roller pair 130 corrects the skew of the medium M that has been touched by the medium M supplied from the medium supply apparatus 1, and then conveys the medium M toward the image forming section 110 and the conveying section 120.

[0072] In the image forming apparatus 101 described above, the medium M on which image formation has been performed by the image forming section 110 is discharged to a discharge section, not shown. Further, in the case where both sides of the medium M are subjected to image formation, the medium M on which image formation has been performed on one side by the image forming section 110 is conveyed again to the image forming section 110 via a circulation path, not shown, and image formation on the remaining side is performed by the image forming section 110.

[0073] As shown in Figure 6 , the medium M is a small-size medium Ml, and the end guard 50 is located on the downstream side in the conveying direction D when the end guard 50 is in the first position PI, as compared with when the end guard 50 is in the second position P2. Figure 7 In this case, the sector gear 73 raises the support member 72 as compared with when the end guard 50 is in the second position P2, and thus the elastic body 71 is elongated in a state in which the pressing member 60 is pressing the upstream end portion of the medium M (see Figure 4B ). Therefore, the elastic body 71 weakens the force with which the pressing member 60 presses downward, and the pressing force Fl with which the pressing member 60 presses the upstream end portion of the medium M downward is weakened (Fl < F2). Therefore, even if the pressing member 60 approaches the conveying mechanism 30, the sag on the upstream side in the conveying direction D of the small-size medium Ml is reduced by the suction of the suction air A3 generated by the suction mechanism 40, and the small-size medium Ml is easily sucked to the conveying mechanism 30.

[0074] Further, the pressing force F1 of the pressing member 60 when the end guard 50 is in the first position P1 can be weaker than the suction force F10 of the suction mechanism 40. Also, the pressing force F1 can be stronger than the vertical upward component of the float air Al blown by the float air blowing mechanism 21, i.e., the float force F20.

[0075] As shown in Figure 7 , the medium M is a large-size medium M2, and the sector gear 73 causes the support member 72 to descend downward when the end guard 50 is in the second position P2, compared to when the end guard 50 is in the first position P1. Therefore, the elastic body 71 is compressed in a state where the pressing member 60 presses the upstream side end portion of the medium M (see Figure 5B ). Thus, the force with which the elastic body 71 presses the pressing member 60 downward is stronger when the end guard 50 is in the second position P2 than when the end guard 50 is in the first position P1, and the pressing force F2 with which the pressing member 60 presses the upstream side end portion of the medium M downward is stronger (F2 > F1). Thus, as shown in Figure 8 , it is possible to prevent the skewing of the large-size medium M2, i.e., the skewing of the large-size medium M2S as shown by the double-dotted line, from the large-size medium M2 extending long at a position upstream of the side guards 81, 82 in the conveying direction D.

[0076] Further, the pressing force F2 of the pressing member 60 when the end guard 50 is in the second position P2 can be stronger than the suction force F10 of the suction mechanism 40. However, if the pressing force F2 is too strong, the uppermost layer of the medium M is sandwiched by the pressing member 60 and the second and subsequent layers of the medium M, which hinders the conveying, and thus the pressing force F2 can be a value that is strong enough not to hinder the conveying of the uppermost layer of the medium M by the conveying mechanism 30. Also, the pressing force F2 of the pressing member 60 when the end guard 50 is in the second position P2 can be stronger than the vertical upward component of the float air Al blown by the float air blowing mechanism 21, i.e., the float force F20, as with the pressing force F1.

[0077] Hereinafter, a summary of the feeding operation of the medium supply device 1 will be described with reference to Figure 6 and Figure 7 .

[0078] First, as shown in Figure 6 and Figure 7 , in a state where the blowing of the float air Al by the float air blowing mechanism 21, the blowing of the separation air A2 by the separation air blowing mechanism 22, and the suction of the suction air A3 by the suction mechanism 40 are all being performed, the uppermost layer of the medium M among the plurality of media M loaded on the loading table 10 is adsorbed to the conveying belt 31.

[0079] When the topmost medium M is adsorbed to the conveyance belt 31, the control section 91 stops the blowing of the floating air Al by the floating air blowing mechanism 21. By thus stopping the blowing of the floating air Al, the second and subsequent media M not adsorbed to the conveyance mechanism 30 fall down, and return to the state of being loaded on the loading table 10.

[0080] Further, the control section 91 starts the conveyance of the topmost medium M by the conveyance mechanism 30 by the drive control of the conveyance mechanism drive section 95. The medium M conveyed by the conveyance mechanism 30 is conveyed toward the conveyance section 120 by the positioning roller pair 130 shown in Fig. 6, and image formation is performed by the image forming section 110. Figure 1

[0081] In the medium supply device 1, after the conveyance of the topmost medium M by the conveyance mechanism 30 is started, in order to adsorb the next medium M (the second medium M) to the conveyance mechanism 30, the control section 91 again starts the blowing of the floating air Al by the floating air blowing mechanism 21. In addition, the blowing of the separating air A2 by the separating air blowing mechanism 22 can be performed all the time during the conveyance of the plurality of media M, and further, the suction of the suction air A3 by the suction mechanism 40 can be temporarily stopped each time one medium M is conveyed, and is again started when the second medium M is adsorbed to the conveyance mechanism 30.

[0082] Further, in the above description, as one example of the linkage member of the pressing force adjustment mechanism 70, i.e., the linkage member that raises the support member 72 in linkage with the movement of the end guard 50 to the downstream side in the conveyance direction D and lowers the support member 72 in linkage with the movement of the end guard 50 to the upstream side in the conveyance direction D, the sector gear 73 is mentioned. However, as the linkage member, it is not limited to the sector gear 73 as long as it is a member that raises and lowers the support member 72 in linkage with the movement of the end guard 50 in the conveyance direction D, for example, by the rotation linkage with the guard shaft 53 or the like.

[0083] Further, as the pressing force adjustment mechanism 70, it can be one that omits the elastic body 71 and the support member 72 presses the pressing member 60 downward, or it can be one that presses the pressing member 60 downward only when the end guard 50 is in the second position P2 among the first position PI and the second position P2. In these cases, the pressing force adjustment mechanism 70 can also enhance the pressing force F2 of the pressing member 60 when the end guard 50 is in the second position P2, compared to when the end guard 50 is in the first position PI.

[0084] ​Further, the pressing force adjusting mechanism 70 increases the pressing forces Fl, F2 when the end guard 50 is in the second position P2 on the upstream side of the conveying direction D, compared to when the end guard 50 is in the first position Pl, but it can also be said that the further the end guard 50 goes to the upstream side of the conveying direction D, the more the pressing forces Fl, F2 are increased. It is preferable that the pressing forces Fl, F2 be increased the further the end guard 50 goes to the upstream side of the conveying direction D, as such. Further, the structure of the media supply device 1 (the respective parts of the pressing force adjusting mechanism 70, the end guard 50, and the like) is merely an example, and can be changed or omitted as appropriate.

[0085] In the above-described embodiment, the media supply device 1 includes the loading table 10, the float air blowing mechanism 21, the conveying mechanism 30, the suction mechanism 40, the end guard 50, the pressing member 60, and the pressing force adjusting mechanism 70. The loading table 10 loads a plurality of media M. The float air blowing mechanism 21 blows float air Al that causes at least the uppermost media M of the plurality of media M loaded on the loading table 10 to float. The conveying mechanism 30 conveys the uppermost media M in the conveying direction D. The suction mechanism 40 causes the uppermost media M to be adsorbed to the conveying mechanism 30 by suction of suction air (suction air A3). The end guard 50 is configured to be movable in the conveying direction D, and limits the position of the upstream end of the plurality of media M in the conveying direction D. The pressing member 60 presses the upstream end of the uppermost media M downward. The pressing force adjusting mechanism 70 is linked to the movement of the end guard 50 in the conveying direction D, and increases the pressing forces Fl, F2 with which the pressing member 60 presses the upstream end of the uppermost media M downward when the end guard 50 is in the second position P2 on the upstream side of the conveying direction D from the first position Pl, compared to when the end guard 50 is in the first position Pl (F2 > Fl).

[0086] Therefore, firstly, by pressing the upstream end of the uppermost medium M downwards using the pressing member 60, overlapping feeding of the second and subsequent mediums M with the uppermost medium M by the conveying mechanism 30 can be suppressed. Furthermore, when a relatively short medium M (e.g., a small-sized medium M1) is loaded onto the loading table 10 in the conveying direction D, the end guard plate 50 is in position 1 P1, and the conveying mechanism 30 and the pressing member 60 are relatively close. In this case, the pressing force F1 of the pressing member 60 is relatively weaker, thus preventing the medium M from failing to be lifted by the rising air A1 or from being adsorbed onto the conveying mechanism 30 in a state where the upstream side of the medium M is significantly lowered. Moreover, when a relatively long medium M (e.g., a large-sized medium M2) is loaded onto the loading table 10 in the conveying direction D, the end guard plate 50 is in position 2 P2, and the conveying mechanism 30 and the pressing member 60 are relatively far apart. In this case, even if the pressing force F2 of the pressing member 60 is relatively increased, poor floating is less likely to occur. Furthermore, by relatively increasing the pressing force F2 of the pressing member 60, it is possible to suppress the oblique movement of the large-sized medium M2, which is prone to occur due to its longer extension on the upstream side of the side guard plates 81 and 82 in the conveying direction D (see reference). Figure 8 The occurrence of large-size media M2S (shown by the double-dotted line) in a diagonal pattern is prevented. Therefore, it is possible to prevent transport defects such as offset (offset caused by the diagonal pattern, misalignment in the width direction) from occurring after the media M is supplied. Therefore, according to this embodiment, in the media supply device 1 equipped with a pressing member 60 that presses the upstream end of the uppermost media M in the transport direction D downward, it is possible to prevent floating defects and transport defects.

[0087] Furthermore, in this embodiment, the pressure adjustment mechanism 70 includes an elastic body 71 that presses the pressing member 60 downward, a support member 72 that supports the upper end of the elastic body 71, and a sector gear 73 (an example of a linkage member) that raises the support member 72 in conjunction with the movement of the end guard plate 50 downstream in the conveying direction D and lowers the support member 72 in conjunction with the movement of the end guard plate 50 upstream in the conveying direction D.

[0088] Therefore, the pressing force F1 and F2 of the pressing member 60 can be adjusted using a simple structure employing an elastomer 71.

[0089] Furthermore, in this embodiment, when the end guard plate 50 is in the first position P1, the pressing pressure F1 is weaker than the attractive force F10 of the attracting mechanism 40 (F1 < F10), and when the end guard plate 50 is in the second position P2, the pressing pressure F2 is stronger than the attractive force F10 (F2 > F10).

[0090] Thus, the floating failure can be more reliably prevented when the end guard 50 is in the first position P1, and the conveyance failure can be more reliably prevented when the end guard 50 is in the second position P2.

[0091] Further, the present application is not limited to the above-described embodiments as they are, and structural elements can be modified and embodied within a range not departing from the gist thereof in the implementation stage. Furthermore, various technical solutions can be formed by appropriately combining a plurality of structural elements disclosed in the above-described embodiments. For example, all the structural elements shown in the embodiments can be appropriately combined. Of course, various modifications and applications can be made within a range not departing from the gist of the present application. Hereinafter, the technical solutions recited in the original claims of the present application are described.

[0092] [Note 1]

[0093] A medium supply apparatus characterized by comprising:

[0094] The medium supply apparatus includes:

[0095] a loading table that loads a plurality of media;

[0096] a floating air blowing mechanism that blows floating air that causes at least an uppermost layer of the plurality of media loaded on the loading table to float;

[0097] a conveying mechanism that conveys the uppermost layer of the media in a conveying direction;

[0098] a suction mechanism that causes the uppermost layer of the media to be adsorbed to the conveying mechanism by suction air;

[0099] an end guard that is configured to be movable in the conveying direction and that limits a position of an upstream side end portion of the plurality of media in the conveying direction;

[0100] a pressing member that presses the upstream side end portion of the uppermost layer of the media downward; and

[0101] a pressing force adjusting mechanism that is linked to movement of the end guard in the conveying direction, and that enhances a pressing force with which the pressing member presses the upstream side end portion of the uppermost layer of the media downward when the end guard is in a second position compared to when the end guard is in a first position, the second position being on an upstream side of the first position in the conveying direction.

[0102] [Note 2]

[0103] The medium supply apparatus according to Note 1, characterized in that:

[0104] The pressing force adjustment mechanism has an elastic body that presses the pressing member downward, a support member that supports an upper end of the elastic body, and a linkage member that raises the support member in conjunction with movement of the end guard to the downstream side in the conveying direction and lowers the support member in conjunction with movement of the end guard to the upstream side in the conveying direction.

[0105] [Para 3]

[0106] The medium supply device according to Para 1 or 2, characterized in that

[0107] The pressing force adjustment mechanism makes the pressing force weaker than the suction force of the suction mechanism when the end guard is in the first position and makes the pressing force stronger than the suction force when the end guard is in the second position.

Claims

1. A medium supply device, characterized in that, The medium supply device includes: A loading platform that holds multiple media; An air-blowing mechanism that blows out air to buoy at least the uppermost layer of the plurality of media loaded on the loading platform. A conveying mechanism that conveys the uppermost medium in the conveying direction; An attraction mechanism that draws in air to adsorb the uppermost medium onto the conveying mechanism; An end guard plate, configured to move in the conveying direction, restricts the position of the upstream end of the plurality of media in the conveying direction; The pressing member presses the upstream end of the uppermost medium downwards; and The pressure adjustment mechanism is linked to the movement of the end plate in the conveying direction. Compared with the end plate being in the first position, when the end plate is in the second position, the pressing force of the pressing member pressing the upstream end of the uppermost medium downward is increased. The second position is located upstream of the first position in the conveying direction.

2. The medium supply device according to claim 1, characterized in that, The pressure adjustment mechanism includes: an elastic body that presses the pressing member downward; a support member that supports the upper end of the elastic body; and a linkage member that, in conjunction with the movement of the end guard plate downstream in the conveying direction, causes the support member to rise, and in conjunction with the movement of the end guard plate upstream in the conveying direction, causes the support member to fall.

3. The medium supply device according to claim 1 or 2, characterized in that, The pressure adjustment mechanism makes the pressing force weaker than the attraction force of the attraction mechanism when the end guard plate is in the first position, and makes the pressing force stronger than the attraction force when the end guard plate is in the second position.

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