Medium transport device

Abstract

To provide a medium transport device capable of feeding multiple types of media suitably.SOLUTION: The medium transport device includes: a guide member having an opening or a notch, and forming a media transport surface; a feed roller disposed in the opening or the notch, and feeding a medium; a separation roller disposed opposite the feed roller; and protrusions disposed on both sides of the separation roller in a medium transport direction. The guide member has recesses located on both sides of the feed roller with respect to the medium transport direction, and the projections are arranged at a position facing the opening or the notch or the recess so that the medium is transported between the projection and the recess, and a tip of the projection is located closer to the side of the feed roller than the nip portion between the feed roller and separation roller.SELECTED DRAWING: Figure 14

Description

[Technical Field]

[0001] The present disclosure relates to a medium transport device, and more particularly to a medium transport device having a feed roller and a separation roller, a control method, and a control program. [Background technology]

[0002] In recent years, media transport devices, such as scanners, that transport and capture multiple media while separating them are being required to transport various types of media, including not only standard PPC (plain paper copier) paper but also thin paper, envelopes, and bound copy paper. Thin paper is more likely to have wrinkles or tears, and its stiffness is also weak. Therefore, when transporting thin paper as a medium, the media is likely to buckle and jam. Furthermore, when transporting media made up of multiple sheets of paper, such as envelopes or copy paper, a force attempting to separate the media is applied to the media, which can cause a media jam. Generally, media transport devices have two feeding modes: a separation mode, in which media are fed while being separated, and a non-separation mode, in which media are fed without being separated. For example, setting the feeding mode of a media transport device to the non-separation mode can prevent media jams, but having to change the feeding mode for each type of media can be inconvenient for users, reducing user convenience. Furthermore, when a plurality of types of media are set together on the mounting table and transported sequentially, it is difficult to change the feeding mode for each type of media.

[0003] A paper feeding device is disclosed that includes a paper feeding means that separates and feeds paper sheets one by one in a convex curled state (see Patent Document 1). This paper feeding device includes a turn guide that turns the separated and fed paper sheets in a convex direction, and a guide member that is provided between the turn guide and the paper feeding means and guides the paper sheets that are turned in the convex direction while correcting the curl in the direction opposite to the convex curl.

[0004] A paper feed conveying device is disclosed that has a paper feed means, a pair of conveying rollers that convey paper fed from the paper feed means, and a paper feed lower guide disposed between the paper feed means and the pair of conveying rollers (see Patent Document 2). This paper feed lower guide has portions where the paper guide surfaces on both ends are higher than the guide surface in the center. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 6-179540 [Patent Document 2] Japanese Patent Application Publication No. 2-305741 Summary of the Invention

[0006] A media transport device is required to appropriately feed a plurality of types of media.

[0007] The purpose of the media transport device is to allow for the proper feeding of multiple types of media.

[0008] A media transport device according to one aspect of the embodiment includes a guide member having an opening or cutout portion and forming a transport surface for the media, a feed roller arranged within the opening or cutout portion and feeding the media, a separation roller arranged opposite the feed roller, and protrusions arranged on the left and right of the separation roller in the media transport direction, the guide member having recesses located on the left and right of the feed roller in the media transport direction, the protrusions being arranged opposite the opening or cutout portion or the recesses so that the media is transported between the protrusions and the recesses, and the tips of the protrusions being located on the feed roller side of the nip portion between the feed roller and the separation roller.

[0009] According to this embodiment, the medium transport device can appropriately feed a plurality of types of media.

[0010] The objects and advantages of the invention will be realized and obtained by means of the elements and combinations particularly pointed out in the claims. Both the foregoing general description and the following detailed description are exemplary and explanatory and are not restrictive of the invention as claimed. [Brief explanation of the drawings]

[0011] [Figure 1] 1 is a perspective view showing a medium conveying device 100 according to an embodiment. [Figure 2] 2 is a diagram for explaining a transport path inside the medium transport device 100. FIG. [Figure 3] FIG. 2 is a schematic diagram for explaining a feeding mechanism 120. [Figure 4] FIG. 2 is a schematic diagram of a feeding mechanism 120 as viewed from above. [Figure 5] FIG. 2 is a schematic diagram of a feeding mechanism 120 as viewed from the downstream side. [Figure 6] 10 is a graph showing the relationship between the length in the width direction A8 and the buckling load for each medium. [Figure 7] 5 is a cross-sectional view taken along the line AA' in FIG. 4. [Figure 8] 10 is a schematic diagram showing a state in which a medium M1 is fed by a feeding mechanism 120. FIG. [Figure 9] FIG. 10 is a perspective view of the feed arm 122 and other components as viewed from the upstream side. [Figure 10] 5 is a cross-sectional view taken along the line BB' in FIG. 4. [Figure 11] FIG. 10 is a perspective view of the feed arm 122 as seen from the upstream side. [Figure 12] 10 is a schematic diagram for explaining a set guide 124 and the like. FIG. [Figure 13] 10 is a schematic diagram for explaining a set guide 124 and the like. FIG. [Figure 14] 10 is a schematic diagram for explaining a set guide 124 and the like. FIG. [Figure 15] 1 is a block diagram showing a schematic configuration of a medium conveying device 100. FIG. [Figure 16]FIG. 2 is a diagram showing a schematic configuration of a storage device 140 and a processing circuit 150. [Figure 17] 10 is a flowchart illustrating an example of the operation of a medium reading process. [Figure 18] FIG. 10 is a schematic diagram for explaining another protrusion 222a. [Figure 19] 10(a) and 10(b) are schematic diagrams for explaining yet another protrusion 322a. [Figure 20] 10(a) and 10(b) are schematic diagrams for explaining another guide member 421. FIG. [Figure 21] 10(a) is a schematic diagram for explaining another feed arm 522, and FIG. 10(b) is a schematic diagram for explaining yet another feed arm 622. FIG. [Figure 22] 10 is a schematic diagram for explaining yet another guide member 721. FIG. [Figure 23] 10 is a schematic diagram for explaining yet another guide member 821. FIG. [Figure 24] 10 is a schematic diagram for explaining yet another guide member 921. FIG. [Figure 25] FIG. 10 is a diagram showing a schematic configuration of another processing circuit 250. DETAILED DESCRIPTION OF THE INVENTION

[0012] A medium conveying device, a control method, and a control program according to one aspect of the present disclosure will be described below with reference to the drawings. However, please note that the technical scope of the present invention is not limited to the embodiments, but extends to the inventions set forth in the claims and their equivalents.

[0013] FIG. 1 is a perspective view showing a medium conveying device 100 configured as an image scanner. The medium conveying device 100 conveys and captures an image of a medium, which is an original document. The medium may be paper, thin paper, thick paper, card, copy paper, envelope, or the like. Copy paper is a medium made of multiple thin sheets bound together, such as carbonless paper. The medium conveying device 100 may also be a facsimile, a copier, a multifunction printer (MFP), or the like. Note that the medium being conveyed may not be an original document but may be a print target or the like, and the medium conveying device 100 may also be a printer, or the like.

[0014] The medium conveying device 100 includes a lower housing 101, an upper housing 102, a loading table 103, an ejection table 104, an operation device 105, a display device 106, and the like.

[0015] The upper housing 102 is disposed in a position that covers the top surface of the medium conveying device 100, and is engaged with the lower housing 101 by a hinge so that it can be opened and closed when a medium becomes jammed or when cleaning the inside of the medium conveying device 100, for example.

[0016] The placement stage 103 engages with the lower housing 101 and places media to be fed and transported on it. The ejection stage 104 engages with the upper housing 102 and places ejected media on it. Note that the ejection stage 104 may also engage with the lower housing 101.

[0017] The operation device 105 has input devices such as buttons and an interface circuit for acquiring signals from the input devices, accepts input operations by a user, and outputs operation signals in response to the user's input operations. The display device 106 has a display such as a liquid crystal display, an organic EL (Electro-Luminescence) display, or the like, and an interface circuit for outputting image data to the display, and displays the image data on the display.

[0018] FIG. 2 is a diagram for explaining the transport path inside the medium transport device 100. As shown in FIG.

[0019] The transport path inside the medium transport device 100 includes a medium sensor 111, a feed roller 112, a separation roller 113, a first transport roller 114, a second transport roller 115, an imaging device 116, a first discharge roller 117, and a second discharge roller 118.

[0020] The number of each of the feed roller 112, separation roller 113, first conveyance roller 114, second conveyance roller 115, first discharge roller 117, and / or second discharge roller 118 is not limited to one, and may be more than one. In this case, the multiple feed rollers 112, separation rollers 113, first conveyance roller 114, second conveyance roller 115, first discharge roller 117, and / or second discharge roller 118 are arranged at intervals in the width direction perpendicular to the medium conveyance direction A1.

[0021] The top surface of the lower housing 101 forms a lower guide 101a of the medium transport path, and the bottom surface of the upper housing 102 forms an upper guide 102a of the medium transport path. In Figure 2, arrow A1 indicates the medium transport direction. Hereinafter, "upstream" refers to the upstream side of the medium transport direction A1, and "downstream" refers to the downstream side of the medium transport direction A1.

[0022] The media sensor 111 is disposed upstream of the feed roller 112 and the separation roller 113. The media sensor 111 has a contact detection sensor and detects whether or not a medium is placed on the placement table 103. The media sensor 111 generates and outputs a first media signal whose signal value changes depending on whether or not a medium is placed on the placement table 103. Note that the media sensor 111 is not limited to a contact detection sensor, and any other sensor capable of detecting the presence or absence of a medium, such as an optical detection sensor, may be used as the media sensor 111.

[0023] The feed roller 112 is provided in the lower housing 101, and separates and feeds the media placed on the mounting table 103 in order from the bottom up. The separation roller 113 is a so-called brake roller or retard roller, and is provided in the upper housing 102, disposed opposite the feed roller 112, and rotates in the opposite direction to the medium feeding direction. Alternatively, the feed roller 112 may be provided in the upper housing 102 and the separation roller 113 in the lower housing 101, and the feed roller 112 may feed the media placed on the mounting table 103 in order from the top up.

[0024] The first conveying roller 114 and the second conveying roller 115 are disposed downstream of the feeding roller 112 and facing each other, and convey the medium fed by the feeding roller 112 and the separation roller 113 to the imaging device 116. The first conveying roller 114 is provided in the lower housing 101, and the second conveying roller 115 is provided in the upper housing 102, above the first conveying roller 114.

[0025] The imaging device 116 is disposed downstream of the first conveyance rollers 114 and captures an image of the medium conveyed by the first conveyance rollers 114. The imaging device 116 includes a first imaging device 116a and a second imaging device 116b disposed opposite each other across the medium conveyance path. The first imaging device 116a has a line sensor based on a CIS (Contact Image Sensor) of a 1:1 optical system type having CMOS (Complementary Metal Oxide Semiconductor) imaging elements linearly arranged in the main scanning direction. The first imaging device 116a also has a lens that forms an image on the imaging element and an A / D converter that amplifies and analog-to-digital (A / D) converts the electrical signal output from the imaging element. The first imaging device 116a captures an image of the surface of the conveyed medium under control of a processing circuit (described later), generates an input image, and outputs it.

[0026] Similarly, the second imaging device 116b has a CIS line sensor with a life-size optical system having CMOS imaging elements linearly arranged in the main scanning direction. The second imaging device 116b also has a lens that forms an image on the imaging element and an A / D converter that amplifies and analog-to-digital (A / D) converts the electrical signal output from the imaging element. The second imaging device 116b captures the back side of the medium being conveyed under control of a processing circuit (described later) to generate and output an input image.

[0027] The medium conveying device 100 may have only one of the first and second imaging devices 116a and 116b, and may read only one side of the medium. Instead of a CIS line sensor with an equal-magnification optical system and a CMOS imaging element, a CIS line sensor with an equal-magnification optical system and a CCD (Charge Coupled Device) imaging element may be used. Alternatively, a reduction optical system line sensor with a CMOS or CCD imaging element may be used.

[0028] The first discharge roller 117 and the second discharge roller 118 are disposed downstream of the imaging device 116 and facing each other, and discharge the medium that has been transported by the first transport roller 114 and the second transport roller 115 and imaged by the imaging device 116 onto the discharge tray 104. The first discharge roller 117 is provided in the lower housing 101, and the second discharge roller 118 is provided in the upper housing 102, above the first discharge roller 117.

[0029] The media placed on the mounting table 103 are conveyed between the lower guide 101a and the upper guide 102a in the media conveying direction A1 by the rotation of the feed roller 112 in the direction of arrow A2 in FIG. 2, i.e., the media feeding direction. The medium conveying device 100 has two feeding modes: a separation mode in which the media are separated while being fed, and a non-separation mode in which the media are fed without being separated. The feed mode is set by the user using the operation device 105 or an information processing device that is communicatively connected to the medium conveying device 100. When the feeding mode is set to the separation mode, the separation roller 113 rotates in the direction of arrow A3, i.e., the opposite direction to the media feeding direction, during media feeding. When multiple media are placed on the mounting table 103, the feed roller 112 and the separation roller 113 act to separate only the media that are in contact with the feed roller 112. This limits the conveyance of media other than the separated media (preventing double feeding). On the other hand, when the feeding mode is set to the non-separation mode, the separation roller 113 rotates in the direction opposite to the arrow A3, that is, in the medium feeding direction.

[0030] The medium is guided by lower guide 101a and upper guide 102a and fed between first conveyor roller 114 and second conveyor roller 115. The medium is fed between first imaging device 116a and second imaging device 116b as first conveyor roller 114 and second conveyor roller 115 rotate in the directions of arrows A4 and A5, respectively. The medium read by imaging device 116 is discharged onto discharge tray 104 as first discharge roller 117 and second discharge roller 118 rotate in the directions of arrows A6 and A7, respectively.

[0031] FIG. 3 is a perspective view for explaining the feeding mechanism 120 of the medium conveying device 100. As shown in FIG.

[0032] 3, the medium conveying device 100 has, as the feeding mechanism 120, a guide member 121 and a feeding arm 122 in addition to the feeding roller 112 and the separation roller 113. In the example shown in FIG. 3, the medium conveying device 100 has two feeding rollers 112 and two separation rollers 113.

[0033] The guide member 121 is a plate-shaped member that is provided on the upper surface of the lower housing 101 so as to form a medium transport surface 121a, and forms part of the lower guide 101a. The guide member 121 has an opening 121b in the center in the width direction A8 that is perpendicular to the medium transport direction, and the feed roller 112 is disposed within the opening 121b.

[0034] The conveying surface 121a of the guide member 121 has recesses 121c located on the left and right of the feed roller 112 in the medium conveying direction A1. In the example shown in Fig. 3, the guide member 121 has two recesses 121c. The recesses 121c are formed so that the downstream side is inclined downward with respect to an area 121d on the conveying surface 121a that is upstream of the recess 121c.

[0035] The feed arm 122 is provided in the upper housing 102, and is disposed upstream of and in the vicinity of the separation roller 113. The feed arm 122 has protrusions 122a extending from the upper housing 102 side toward the lower housing 101 side, that is, from the separation roller 113 side toward the feed roller 112 side. The protrusions 122a are disposed on the left and right sides of the separation roller 113 in the medium conveying direction A1. In particular, the protrusions 122a are disposed in positions facing the openings 121b of the guide member 121. In the example shown in FIG. 3, the feed arm 122 has two protrusions 122a.

[0036] FIG. 4 is a schematic diagram of the feeding mechanism 120 as viewed from above.

[0037] 4, the recess 121c is provided in an area R1 that is the center and outside the opening 121b in the width direction A8. The recess 121c is also provided in an area R2 that includes the nip portion between the feed roller 112 and the separation roller 113 in the medium transport direction A1. In the example shown in FIG. 4, the upstream end P3 of the recess 121c is located downstream of the upstream end of the feed roller 112, but the recess 121c may be provided in an area that includes the entire feed roller 112 and the separation roller 113 in the medium transport direction A1.

[0038] 5 is a schematic diagram of the feeding mechanism 120 as seen from the downstream side. In FIG. 5, for better visibility, parts other than the protrusion 122a of the feeding arm 122 are not shown.

[0039] 5, the tip (lower end) of the protrusion 122a is located closer to the feed roller 112 (lower) than the nip between the feed roller 112 and the separation roller 113. The medium M1 fed by the feed roller 112 and the separation roller 113 is transported between the protrusion 122a of the feed arm 122 and the recess 121c of the guide member 121.

[0040] The protrusion 122a presses the area of ​​the fed medium M1 facing the recess 121c downward in the width direction A8, lower than the inner area that contacts the feed roller 112 and the separation roller 113 and the area outside the recess 121c. This causes the fed medium M1 to undulate in the width direction A8, allowing the medium conveying device 100 to stiffen the medium and improve the rigidity of the medium moving in the medium conveying direction A1. Therefore, even when thin paper with low stiffness is conveyed as the medium, the medium conveying device 100 can prevent the medium from buckling and prevent the medium from jamming. Furthermore, even when a medium made of multiple sheets of paper, such as an envelope or copy paper, is conveyed, the medium has enough rigidity to withstand the separation force of the separation roller 113, allowing the medium conveying device 100 to prevent the medium from jamming.

[0041] Furthermore, the protrusion 122a presses the area of ​​the medium M1 facing the recess 121c downward in the width direction A8, below the inner area that contacts the feed roller 112 and the separation roller 113. As a result, the height position of the inner area of ​​the medium M1 that contacts the feed roller 112 and the separation roller 113 and the area outside of that area changes, in a direction perpendicular to the conveying surface 121a. Therefore, when multiple media are set together on the loading platform 103 and fed, the frictional force between the media sandwiched between the feed roller 112 and the separation roller 113 is less likely to propagate outward in the width direction A8. Therefore, the medium conveying device 100 can improve the separation performance of regular paper such as PPC paper, while reducing jams of special media such as thin paper, envelopes, or copy paper.

[0042] Furthermore, on conveying surface 121a of guide member 121, the area outside recess 121c in width direction A8 is located closer to (below) feed roller 112 than the nip between feed roller 112 and separation roller 113. If conveying surface 121a were located above the nip, the medium would be less likely to come into contact with feed roller 112, reducing the conveying force of the medium. By locating conveying surface 121a below the nip, medium conveying device 100 can effectively stiffen the medium while preventing a reduction in the conveying force of the medium.

[0043] Furthermore, a gap is provided between the tip of the protrusion 122a and the recess 121c in the height direction perpendicular to the conveying surface 121a, so that the medium is not obstructed by the protrusion 122a and the recess 121c and is fed smoothly between the protrusion 122a and the recess 121c.

[0044] It is preferable that the distance W [mm] from the outer edge of the feed roller 112 to the outer edge of the recess 121c be set so as to satisfy the following formula (1). W = (Wc - Wr) / 2 > 10 [mm] (1) Here, Wc is the length [mm] between both ends of the recess 121c in the width direction A8, and Wr is the length [mm] between both ends of the feed roller 112 in the width direction A8. The length Wr between both ends of the feed roller 112 in the width direction A8 is set to a length equal to or less than the minimum medium size width supported by the medium conveying device 100 (for example, the length in the short direction of an A8 size).

[0045] Furthermore, it is preferable that the length Wc between both ends of the recess 121c in the width direction A8 is set so as to satisfy the following formula (2). (Wm-Wc) / 2>10[mm] (2) Here, Wm is the minimum medium size width of the medium to be fed, and is set to, for example, 148 mm, which is the short side length of an A5 size (long side length of an A6 size). As a result, in the width direction A8, both ends of the medium to be fed are positioned outside the recess 121c, and the outer area of ​​the medium is located above the area facing the recess 121c, so that the medium conveying device 100 can bend the medium well.

[0046] The buckling load T [gf] required to buckle the medium being fed is calculated by the following formula (3). T=π 2 ×E×M / L 2 (3) Here, E is the Young's modulus of the medium [GPa]. L is the length [mm] of the width direction A8 of the area where the load is applied within the medium. M is the moment of inertia. The moment of inertia M is a cross-sectional characteristic that indicates the resistance of a material to deformation due to bending force, and is calculated using the following formula (4). M=H 3 ×B / 12 (4) Here, H is the thickness [mm] of the medium, and B is the length [mm] in the medium transport direction A1 of the area to which the load is applied within the medium.

[0047] FIG. 6 is a graph showing the relationship between the length in the width direction A8 and the buckling load for each medium.

[0048] In Figure 6, graph G1 shows the buckling load of carbonless paper with a Young's modulus of 3 GPa, and graph G2 shows the buckling load of thin paper with a Young's modulus of 2.2 GPa. The horizontal axis of Figure 6 represents the length (mm) of each medium in the width direction A8, and the vertical axis represents the buckling load (gf) of each medium. The length (in the media transport direction A1) of the area where the load is applied within each medium shown in Figure 6 is 40 mm. As shown in equation (3), the buckling load required to buckle the medium is inversely proportional to the square of the length (in the width direction A8) of the area where the load is applied within the medium. As shown in Figure 6, when the length (in the width direction A8) of the medium is 10 mm or less, the buckling load required to buckle the medium increases sharply.

[0049] Therefore, as shown in formula (1), by making the distance W from the outer edge of feed roller 112 to the outer edge of recess 121c greater than 10 mm, medium conveying device 100 can satisfactorily buckle the medium with a sufficiently small buckling load. This allows medium conveying device 100 to buckle the area of ​​the medium facing recess 121c using protrusion 122a and the weight of the medium without using a special pressing member, thereby enabling medium conveying device 100 to satisfactorily stiffen the medium.

[0050] Furthermore, the length Wa between both ends of the two protrusions 122a in the width direction A8 is set to be greater than the length Wr between both ends of the feed roller 112 in the width direction A8, and to be equal to or less than the minimum medium size width supported by the medium conveying device 100. In other words, the two protrusions 122a are positioned outside the two feed rollers 112 and in the vicinity of the two feed rollers 112. This allows the protrusions 122a to reliably stiffen even small size paper such as A5 size, and the medium conveying device 100 can prevent jams of small media.

[0051] Fig. 7 is a cross-sectional view taken along line AA' in Fig. 4. That is, Fig. 7 is a diagram of the feeding mechanism 120 as seen from the side (as seen from the width direction A8).

[0052] 7, the separation roller 113 is supported by a separation roller cover 123. The separation roller cover 123 is attached to the upper housing 102 via an elastic member (not shown) such as a spring or rubber, and is biased downward by the elastic member. As a result, the separation roller cover 123 applies a biasing force to the separation roller 113 so that the separation roller 113 presses against the feed roller 112.

[0053] The feeding arm 122 is stored in the separation roller cover 123 so as to be movable in the vertical direction relative to the separation roller cover 123. The feeding arm 122 is attached to the separation roller cover 123 via an elastic member (not shown) such as a spring or rubber, and is urged downward relative to the separation roller cover 123 by the elastic member.

[0054] Contact surface 122b of protrusion 122a of feed arm 122, which comes into contact with the medium fed by feed roller 112, is formed so as to be parallel to region 121d, which is located upstream of recess 121c of conveyance surface 121a of guide member 121 in medium conveyance direction A1. Contact surface 122b being parallel to region 121d does not necessarily mean that they are completely parallel, but rather means that the angle between contact surface 122b and region 121d is a predetermined angle (for example, 5°) or less. By forming contact surface 122b parallel to region 121d, protrusion 122a can smoothly guide the medium guided by conveyance surface 121a of guide member 121 downstream.

[0055] If the contact surface 122b is tilted so that the downstream side of the contact surface 122b sinks relative to the region 121d (toward the feed roller 112), the magnitude of the load that the medium receives from the protrusions 122a gradually increases as the medium is transported, reducing the medium transport force. Furthermore, in this case, when the medium is transported at an angle, the magnitude of the load that the medium receives from the left and right protrusions 122a differs, further increasing the inclination of the medium. On the other hand, if the contact surface 122b is tilted so that the downstream side of the contact surface 122b rises relative to the region 121d (toward the separation roller 113), the force that the protrusions 122a apply to stiffen the medium is reduced. By arranging the contact surface 122b so that it is parallel to the region 121d, the medium transport device 100 can effectively stiffen the medium while reducing the medium transport force and preventing the medium from becoming skewed.

[0056] When viewed from the width direction A8 perpendicular to the medium conveying direction A1, the protrusion 122a is arranged so that at least a portion thereof overlaps with the nip portion between the feed roller 112 and the separation roller 113 and with a region of the feed roller 112 upstream of the nip portion in the medium conveying direction A1. That is, the upstream end P1 of the protrusion 122a is arranged downstream of the upstream end of the feed roller 112 and upstream of the upstream end of the nip portion between the feed roller 112 and the separation roller 113 in the medium conveying direction A1. This allows the protrusion 122a to stiffen the fed medium just before the nip portion between the feed roller 112 and the separation roller 113. Therefore, the medium conveying device 100 can improve the rigidity of the medium, thereby preventing the medium from jamming when the medium enters the nip portion. Furthermore, even if the leading edge of the medium being fed is curled upward, the curled portion is held down by the protrusion 122a, so the medium is guided well into the nip between the feed roller 112 and the separation roller 113.

[0057] Furthermore, the downstream end P2 of the protrusion 122a is located downstream of the straight line L1 connecting the center O1 of the feed roller 112 and the center O2 of the separation roller 113 in the medium conveying direction A1, and upstream of the downstream end of the feed roller 112. Furthermore, the end P2 is located near the downstream end of the nip portion between the feed roller 112 and the separation roller 113 in the medium conveying direction A1. In particular, the end P2 is located upstream of the downstream end of the nip portion in the medium conveying direction A1. Note that the end P2 may also be located downstream of the downstream end of the nip portion in the medium conveying direction A1. Generally, medium jams are likely to occur during the period from just before the medium enters the nip portion until the medium is passing through the nip portion. By extending the protrusion 122a to the vicinity of the downstream end of the nip portion, the protrusion 122a stiffens the medium near the nip portion. Therefore, the medium conveying device 100 can improve the rigidity of the medium, and can prevent the medium from jamming while the medium is passing through the nip portion.

[0058] Furthermore, in the height direction perpendicular to the conveying surface 121a, the protrusion 122a is arranged so that at least a portion thereof is located below the upper end of the feed roller 112. The lower surface of the protrusion 122a is arranged so as to be located below the upper end of the feed roller 112 by a predetermined distance T1 (for example, 0.1 mm or more and 5 mm or less).

[0059] Fig. 8 is a schematic diagram showing how the medium M1 is fed by the feeding mechanism 120. Fig. 8 is a schematic diagram of the feeding mechanism 120 as seen from the side.

[0060] 8, when the outer portion of the medium M1 being fed in the width direction A8 is pressed down by the protrusion 122a, the portion facing the feed roller 112 extends along the surface of the feed roller 112. As a result, the medium M1 bends in a wavy manner in the medium conveying direction A1, which allows the medium conveying device 100 to stiffen the medium M1 and improve the rigidity of the medium M1 traveling in the medium conveying direction A1. Therefore, even when thin paper, envelopes, or copy paper are being conveyed as the medium, the medium conveying device 100 can prevent the medium from jamming.

[0061] Fig. 9 is a perspective view of the feed arm 122, the feed roller 112, and the separation roller 113 as viewed from the upstream side. Fig. 10 is a cross-sectional view taken along line BB' in Fig. 4. That is, Fig. 10 is a view of the feed mechanism 120 as viewed from the side. Fig. 11 is a perspective view of the feed arm 122 as viewed from the upstream side.

[0062] As shown in FIG. 9, the feeding arm 122 further includes a pressure roller 122c and a second protrusion 122d.

[0063] As shown in FIGS. 9 and 10 , the pressure roller 122c faces the feed roller 112 and is disposed upstream of the nip portion between the feed roller 112 and the separation roller 113 in the medium conveying direction A1. The pressure roller 122c is disposed near the upstream end P1 of the protrusion 122a in the medium conveying direction A1. The pressure roller 122c presses the medium fed by the feed roller 112 toward the feed roller 112 from above. In the example shown in FIGS. 9 and 10 , the feed arm 122 has two pressure rollers 122c. The pressure roller 122c sandwiches the medium between itself and the feed roller 112 and applies a conveying force to the medium fed by the feed roller 112. This enables the medium conveying device 100 to feed the medium well.

[0064] The pressure roller 122c is provided on the feed arm 122 on which the protrusion 122a is provided, and is configured to move in conjunction with the protrusion 122a. This allows the medium conveying device 100 to simply control the feed arm 122 and the pressure roller 122c, making it possible to reduce the development costs of the medium conveying device 100. Furthermore, by configuring the protrusion 122a and the pressure roller 122c as a single component, the medium conveying device 100 can reduce the cost and weight of the device.

[0065] In the width direction A8, the pressure roller 122c presses down on the center of the medium, which makes it easier for the outer portions of the medium to lift up. However, because the outer portions of the medium are pressed down by the protrusions 122a, the medium conveying device 100 can prevent the side of the lifted medium from coming into contact with the rubber surface of the separation roller 113 and causing the medium to buckle.

[0066] 9 and 11, the second protrusion 122d faces the feed roller 112 and is disposed upstream of the nip portion between the feed roller 112 and the separation roller 113 in the medium conveying direction A1. That is, the second protrusion 122d is positioned closer to the separation roller 113 (upper side) than the nip portion between the feed roller 112 and the separation roller 113. The second protrusion 122d guides the medium fed by the feed roller 112 to the nip portion between the feed roller 112 and the separation roller 113. In the example shown in FIGS. 9 and 11, the feed arm 122 has two second protrusions 122d for one feed roller 112 that are disposed so as to sandwich each pressure roller 122c in the width direction A8, for a total of four second protrusions 122d.

[0067] The medium being fed is guided by the second protrusion 122d into the nip portion between the feed roller 112 and the separation roller 113. In particular, even if the medium being fed is a medium with a curled leading edge or thin paper, the medium conveying device 100 can more reliably guide the medium into the nip portion. The medium conveying device 100 can prevent the portion of the medium facing the feed roller 112 from lifting up using the second protrusion 122d, while preventing the portion of the medium not facing the feed roller 112 from lifting up using the protrusion 122a. This allows the medium conveying device 100 to more effectively prevent the leading edge of the medium from lifting up, and can prevent the medium with the lifted leading edge from being bounced up by the separation roller 113, causing the medium to buckle.

[0068] In particular, the second protrusion 122d is arranged to overlap the pressure roller 122c when viewed from the width direction A8. That is, in the medium conveying direction A1, the upstream end of the second protrusion 122d is arranged near the pressure roller 122c, and the downstream end of the second protrusion 122d is arranged near the nip portion between the feed roller 112 and the separation roller 113. This allows the second protrusion 122d to appropriately guide the medium pressed by the pressure roller 122c to the nip portion between the feed roller 112 and the separation roller 113. Note that the upstream end of the second protrusion 122d is arranged downstream of the pressure roller 122c. Alternatively, the upstream end of the second protrusion 122d may be arranged upstream of the pressure roller 122c.

[0069] Furthermore, the pressure roller 122c and / or the second protrusion 122d may be omitted.

[0070] Fig. 12 is a schematic diagram for explaining the set guide 124 and the flap 125. Fig. 12 is a side view of the feeding mechanism 120 before feeding a medium.

[0071] As shown in FIG. 12, the feeding mechanism 120 further includes a set guide 124 and a flap 125 .

[0072] The setting guide 124 is an example of a second guide member and is a guide for setting the medium. The setting guide 124 is disposed at a position facing the feed roller 112 and the separation roller 113 in the medium transport direction A1. The setting guide 124 is provided in the lower housing 101 so as to be able to swing (rotate) downward (in the direction of arrow A9 in FIG. 12) according to a driving force from a motor (not shown). Before the medium is fed, the setting guide 124 is disposed at a first position (the position in FIG. 12) that limits contact between the medium M2 placed on the placement table 103 and the feed roller 112 and the pressure roller 122c, and supports the underside of the medium M2 placed on the placement table 103.

[0073] The flap 125 is a stopper that prevents the medium M2 from entering the nip position between the feed roller 112 and the separation roller 113 before the medium is fed. The flap 125 is disposed in a position facing the set guide 124 in the medium transport direction A1. The flap 125 is provided on the feed arm 122 so as to be able to swing (rotate) downstream (in the direction of arrow A10 in FIG. 12) and is pressed upstream (in the opposite direction to arrow A10) by a spring (not shown). Before the medium is fed, the flap 125 engages with the set guide 124 that is disposed in a first position and prevents the medium M2 from entering the nip position between the feed roller 112 and the separation roller 113. The flap 125 is provided to move in conjunction with the feed arm 122, and when the flap 125 is engaged with the set guide 124, the feed arm 122 is supported by the flap 125 and the set guide 124, preventing the feed arm 122 from moving downward. Therefore, in FIG. 12 , the feed arm 122 is stored in the separation roller cover 123.

[0074] 13 is a schematic diagram for explaining the set guide 124 and the flap 125 during medium feeding. FIG. 13 is a side view of the feeding mechanism 120 during medium feeding.

[0075] 13, when medium feeding starts, the set guide 124 swings downward (in the direction of arrow A9) from the conveying surface 121a. As a result, the set guide 124 is positioned at a second position (positioning position in FIG. 13) that allows contact between the medium M2 placed on the mounting table 103 and the feed roller 112 and the pressure roller 122c during medium feeding, and is separated from the underside of the medium M2 placed on the mounting table 103.

[0076] When the set guide 124 is placed in the second position, the engagement between the flap 125 and the set guide 124 is released. As a result, the flap 125 is pushed by the leading edge of the medium M2 placed on the placement table 103 and swings downstream (in the direction of arrow A10), allowing the medium M2 to enter the nip position between the feed roller 112 and the separation roller 113. In this way, when the set guide 124 is placed in the second position, the flap 125 allows the medium M2 to enter the nip position between the feed roller 112 and the separation roller 113.

[0077] Furthermore, as described above, since the feed arm 122 is biased downward by the elastic member, the disengagement of the flap 125 and the set guide 124 causes the feed arm 122 to move downward (toward the feed roller 112). In the example shown in FIGS. 12 and 13, the amount of media M2 placed on the mounting table 103 is sufficiently small. In this case, the feed roller 112 first contacts the lowest medium among the media M2 placed on the mounting table 103, and then the pressure roller 122c contacts the highest medium among the media M2 placed on the mounting table 103. In other words, when the set guide 124 moves from the first position to the second position, if the amount of media placed on the mounting table 103 is less than a predetermined amount, the pressure roller 122c is arranged to contact the media placed on the mounting table 103 after the feed roller 112.

[0078] When the amount of media placed on the mounting table 103 is small, if the pressure roller 122c presses the media and the feed roller 112 starts to rotate, the leading edge of the media is likely to bend upward, making it more likely for the media to jam. When the amount of media is less than a predetermined amount, the medium conveying device 100 has the feed roller 112 come into contact with the media before the pressure roller 122c does and starts feeding the media, thereby preventing the leading edge of the media from bending upward and causing a media jam.

[0079] Fig. 14 is a schematic diagram for explaining the set guide 124 and the flap 125 when a large amount of media M3 is placed on the placement table 103. Fig. 14 is a side view of the feeding mechanism 120 immediately after starting to feed media when a large amount of media M3 is placed on the placement table 103.

[0080] As described above, when media feeding begins, the set guide 124 is positioned at the second position, the flap 125 is disengaged from the set guide 124, and the feed arm 122 moves downward. As shown in FIG. 14 , when a large amount of media M3 is placed on the mounting table 103, the feed arm 122 moves downward before the set guide 124 moves all the way down. Therefore, before the feed roller 112 contacts the lowest medium among the media M3 placed on the mounting table 103, the pressure roller 122c contacts the highest medium among the media M3 placed on the mounting table 103. In other words, when the set guide 124 moves from the first position to the second position, if the amount of media placed on the mounting table 103 is equal to or greater than a predetermined amount, the pressure roller 122c is positioned to contact the media placed on the mounting table 103 before the feed roller 112.

[0081] When a large amount of media is placed on the mounting table 103, the feed roller 112 starts rotating while the pressure roller 122c is pressing the media, allowing the feed roller 112 to smoothly feed out the media. In particular, when a large amount of media is placed on the mounting table 103, the elastic member applies a greater urging force to the media than when a small amount of media is placed. For example, if the elastic member is a compression spring, the magnitude of the urging force is the product of the amount of compression of the spring multiplied by the spring constant. When a large amount of media is placed on the mounting table 103, the amount of compression of the spring is large, and a greater urging force is applied to the media by the pressure roller 122c, allowing the feed roller 112 to smoothly feed out the media.

[0082] Furthermore, when a large amount of media is placed on the placement table 103, the leading edge of the lowest medium to be fed is pressed down by the weight of the media placed above it, making it less likely that the leading edge of the medium will bend upward. Therefore, when a large amount of media is placed on the placement table 103 and the likelihood of a media jam occurring is low, the medium conveying device 100 prioritizes the ease of feeding the media, making it possible to feed the media well.

[0083] FIG. 15 is a block diagram showing a schematic configuration of the medium conveying device 100. As shown in FIG.

[0084] In addition to the above-described components, the medium conveying device 100 further includes a motor 131, an interface device 132, a storage device 140, a processing circuit 150, and the like.

[0085] The motor 131 has one or more motors, and rotates the feed roller 112, separation roller 113, first conveyance roller 114, second conveyance roller 115, first discharge roller 117, and second discharge roller 118 to convey the medium in response to a control signal from the processing circuit 150. Note that one of the first conveyance roller 114 and the second conveyance roller 115 may be a driven roller that rotates following the rotation of the other roller. Also, one of the first discharge roller 117 and the second discharge roller 118 may be a driven roller that rotates following the rotation of the other roller. Also, the motor 131 moves the set guide 124 between the first position and the second position in response to a control signal from the processing circuit 150.

[0086] The interface device 132 has an interface circuit conforming to a serial bus such as USB, and is electrically connected to an information processing device (not shown) (for example, a personal computer, a personal digital assistant, etc.) to transmit and receive input images and various information. Alternatively, instead of the interface device 132, a communication unit having an antenna for transmitting and receiving wireless signals and a wireless communication interface device for transmitting and receiving signals via a wireless communication line in accordance with a predetermined communication protocol may be used. The predetermined communication protocol is, for example, a wireless LAN (Local Area Network). The communication unit may have a wired communication interface device for transmitting and receiving signals via a wired communication line in accordance with a communication protocol such as a wired LAN.

[0087] The storage device 140 includes a memory device such as a RAM (Random Access Memory) or a ROM (Read Only Memory), a fixed disk device such as a hard disk, or a portable storage device such as a flexible disk or optical disk. The storage device 140 also stores computer programs, databases, tables, and the like used for various processes of the medium conveying device 100. The computer programs may be installed into the storage device 140 from a computer-readable portable recording medium using a known setup program or the like. The portable recording medium is, for example, a CD-ROM (Compact Disc Read Only Memory), a DVD-ROM (Digital Versatile Disc Read Only Memory), or the like.

[0088] The processing circuit 150 operates based on a program stored in advance in the storage device 140. The processing circuit is, for example, a CPU (Central Processing Unit). The processing circuit 150 may be a DSP (Digital Signal Processor), an LSI (Large Scale Integration), an ASIC (Application Specific Integrated Circuit), an FPGA (Field-Programmable Gate Array), or the like.

[0089] The processing circuit 150 is connected to the operation device 105, the display device 106, the medium sensor 111, the imaging device 116, the motor 131, the interface device 132, the storage device 140, etc., and controls each of these components. Based on the medium signal received from the medium sensor 111, the processing circuit 150 controls the driving of the motor 131, controls the imaging of the imaging device 116, etc., acquires an input image from the imaging device 116, and transmits it to the information processing device via the interface device 132.

[0090] FIG. 16 is a diagram showing a schematic configuration of the storage device 140 and the processing circuit 150. As shown in FIG.

[0091] 16, the storage device 140 stores a control program 141, an image acquisition program 142, and the like. Each of these programs is a functional module implemented by software running on a processor. The processing circuitry 150 reads each program stored in the storage device 140 and operates in accordance with the read program. As a result, the processing circuitry 150 functions as a control unit 151 and an image acquisition unit 152.

[0092] FIG. 17 is a flowchart showing an example of the operation of the medium reading process of the medium conveying device 100.

[0093] An example of the operation of the medium reading process of the medium conveying device 100 will be described below with reference to the flowchart shown in Fig. 17. The flow of the operation described below is executed mainly by the processing circuit 150 in cooperation with each element of the medium conveying device 100 based on a program previously stored in the storage device 140. Before the flowchart shown in Fig. 17 is executed, i.e., before feeding the medium, the set guide 124 is positioned at the first position.

[0094] First, the control unit 151 waits until the user inputs an instruction to read a medium using the operation device 105 or the information processing device, and an operation signal instructing the reading of a medium is received from the operation device 105 or the interface device 132 (step S101).

[0095] Next, control unit 151 acquires a medium signal from medium sensor 111, and determines whether or not a medium is placed on mounting table 103 based on the acquired medium signal (step S102). If no medium is placed on mounting table 103, control unit 151 ends the series of steps.

[0096] On the other hand, if a medium is placed on the placement table 103, the control unit 151 drives the motor 131 to move the set guide 124 from the first position to the second position. The control unit 151 also drives the motor 131 to rotate the feed roller 112, the separation roller 113, the first conveyance roller 114, the second conveyance roller 115, the first discharge roller 117, and / or the second discharge roller 118 to convey the medium (step S103).

[0097] Next, the control unit 151 causes the imaging device 116 to capture an image of the medium, acquires an input image from the imaging device 116, and outputs the acquired input image by transmitting it to the information processing device via the interface device 132 (step S104).

[0098] Next, control unit 151 determines whether or not a medium remains on mounting table 103 based on the medium signal received from medium sensor 111 (step S105). If a medium remains on mounting table 103, control unit 151 returns the process to step S104 and repeats the processes of steps S104 and S105.

[0099] On the other hand, if no media remain on the mounting table 103, the control unit 151 controls the motor 131 to stop the feed roller 112, the separation roller 113, the first conveying roller 114, the second conveying roller 115, the first discharge roller 117, and / or the second discharge roller 118. The control unit 151 also controls the motor 131 to move the set guide 124 from the second position to the first position (step S106), thereby completing the series of steps.

[0100] As described above in detail, medium conveying device 100 has recess 121c in the area surrounding feed roller 112 on medium conveying surface 121a. Furthermore, medium conveying device 100 has protrusion 122a that guides the area of ​​the medium outside feed roller 112 toward feed roller 112 from the nip between feed roller 112 and separation roller 113. This makes it possible for medium conveying device 100 to prevent medium jams from occurring when various types of media, such as thin paper, envelopes, or copy paper, are conveyed. Therefore, medium conveying device 100 can properly feed multiple types of media.

[0101] Furthermore, the medium conveying device 100 can now convey bound media such as envelopes or copy paper even when the feeding mode is set to the non-separation mode. This allows the medium conveying device 100 to continuously convey multiple envelopes or copy paper. Furthermore, the user no longer needs to change the feeding mode setting when conveying bound media such as envelopes or copy paper, and the medium conveying device 100 can improve user convenience.

[0102] Fig. 18 is a schematic diagram for explaining the protrusion 222a in a medium conveying device according to another embodiment. Fig. 18 is a schematic diagram of the feeding mechanism 220 as seen from the downstream side. In Fig. 18, to improve visibility, parts other than the protrusion 222a of the feeding arm are not shown.

[0103] 18, the medium conveying device according to this embodiment has a feeding mechanism 220 instead of the feeding mechanism 120, and the feeding mechanism 220 has a protrusion 222a instead of the protrusion 122a. The protrusion 222a has a similar configuration to the protrusion 122a.

[0104] However, the tip (lower end) of protrusion 222a has a rounded shape. That is, the contact surface of protrusion 222a that comes into contact with the medium fed by feed roller 112 has an R-shape. As a result, when carbonless paper is fed as medium M4, the medium conveying device can prevent the carbonless paper from coming into contact with the tip of protrusion 222a and becoming discolored. Furthermore, when an envelope, cardboard, or the like is fed as the medium, the medium conveying device can prevent the tip of protrusion 222a from causing vertical streaks on the medium.

[0105] As described above in detail, the medium transport device is now able to properly feed a plurality of types of media even when using the R-shaped protrusion 222a.

[0106] Figures 19(a) and (b) are schematic diagrams illustrating a protrusion 322a in a medium conveying device according to yet another embodiment. Figures 19(a) and (b) are schematic diagrams of a feeding mechanism 320 viewed from the downstream side. In Figures 19(a) and (b), to improve visibility, portions other than the protrusion 322a of the feeding arm are omitted. Figure 19(a) shows a state in which a medium M5 with low rigidity, such as thin paper or copy paper, is being fed, and Figure 19(b) shows a state in which a medium M6 with high rigidity, such as thick paper, is being fed.

[0107] 19(a) and 19(b), the medium conveying device according to this embodiment has a feeding mechanism 320 instead of the feeding mechanism 120, and the feeding mechanism 320 has a protrusion 322a instead of the protrusion 122a. The protrusion 322a has a similar configuration to the protrusion 122a.

[0108] However, the protrusion 322a includes a fixed portion 322e and a movable portion 322f. The fixed portion 322e and the movable portion 322f are formed of a rigid material such as metal. The fixed portion 322e is fixed to the feed arm. The movable portion 322f is supported by the fixed portion 322e via an elastic member 322g so as to be swingable outward in the width direction A8 (in the direction of arrow A11). The elastic member 322g is a torsion coil spring or the like, and applies a force to the movable portion 322f toward the inside in the width direction A8 (in the opposite direction to arrow A11) by a stopper (not shown) so that the movable portion 322f stops at a position approximately perpendicular to the conveying surface 121a (the position shown in FIG. 19(a)).

[0109] As shown in FIG. 19(a), if the rigidity of the medium M5 being fed is low, the medium M5 is bent by the protrusion 322a. Therefore, the medium conveying device 100 can stiffen the medium M5, which has low rigidity, and improve the rigidity of the medium M5 moving in the medium conveying direction A1. On the other hand, as shown in FIG. 19(b), if the rigidity of the medium M6 being fed is high, the protrusion 322a is caused to swing outward in the width direction A8 (in the direction of arrow A11) by the medium M6. Therefore, the medium conveying device 100 can prevent the highly rigid medium M6 from being deformed by the protrusion 322a and damaging the medium M6. For highly rigid medium M6, the likelihood of buckling and jamming is sufficiently low even if the protrusion 322a does not stiffen the medium M6.

[0110] In this way, the protrusion 322a has elasticity as a whole, which allows the medium conveying device to prevent jams of low-rigidity media and prevent damage to high-rigidity media.

[0111] The protrusion 322a may be integrally formed from a flexible material such as rubber or resin. In this case, the protrusion 322a is elastic as a whole. Even in this case, the medium conveying device can prevent jams of low-rigidity media while preventing damage to high-rigidity media. Furthermore, by forming the protrusion 322a as a single unit, the medium conveying device can reduce the cost and weight of the device.

[0112] As described above in detail, the medium transport device is now able to properly feed multiple types of media even when using elastic protrusions 322a.

[0113] Figures 20(a) and (b) are schematic diagrams illustrating a guide member 421 in a medium conveying device according to yet another embodiment. Figures 20(a) and (b) are schematic diagrams of a feed mechanism 420 viewed from the downstream side. In Figures 20(a) and (b), to improve visibility, parts other than the protrusion 122a of the feed arm 122 are omitted from the illustration. Figure 20(a) shows a state in which a light medium M7, such as thin paper or copy paper, is being fed, and Figure 20(b) shows a state in which a heavy medium M8, such as cardboard, is being fed.

[0114] 20(a) and 20(b), the medium conveying device according to this embodiment has a feeding mechanism 420 instead of the feeding mechanism 120, and the feeding mechanism 420 has a guide member 421 instead of the guide member 121. The guide member 421 has a similar configuration to the guide member 121.

[0115] However, the guide member 421 has a moving portion 421d that is positioned outside the recessed portions 421c located on the left and right sides of the feed roller 112 in the width direction A8, which is perpendicular to the medium conveyance direction A1. An elastic member 421e is provided between the moving portion 421d and the base of the guide member 421. The elastic member 421e is a compression coil spring, rubber, or the like, and applies an upward force (in the direction of arrow A12) to the moving portion 421d. The weight of the medium present on the moving portion 421d causes the moving portion 421d to push back against the elastic member 421e and move downward. In other words, the moving portion 421d is provided to be movable in a direction perpendicular to the conveyance surface 421a depending on the weight of the medium being fed.

[0116] As a result, when a light medium M7, such as thin paper, is fed, the position of moving section 421d is raised, and the difference in level between the upper surface of moving section 421d and recessed section 421c is sufficiently large. This allows the medium conveying device to provide sufficient stiffness to medium M7. On the other hand, when a heavy medium M8, such as thick paper, is fed, the position of moving section 421d is lowered, and the difference in level between the upper surface of moving section 421d and recessed section 421c is sufficiently small. This allows the medium conveying device to prevent medium M8 from being deformed by recessed section 421c and causing damage to medium M8.

[0117] 20(a), when elastic member 421e is not contracted, moving portion 421d is positioned at a first position (position shown in FIG. 20(a)) that is higher than the upper surface of feed roller 112. As a result, when light medium M7, such as thin paper, is fed, the step between the upper surface of moving portion 421d and recess 421c becomes sufficiently large, allowing the medium conveying device to provide sufficient stiffness to medium M7.

[0118] 20(b), when elastic member 421e is most contracted, moving portion 421d is positioned at a second position (position shown in FIG. 20(b)) that is lower than the upper surface of feed roller 112. As a result, when heavy medium M8, such as cardboard, is fed, feed roller 112 protrudes from the upper surface of moving portion 421d, and the medium conveying device can impart a sufficient conveying force to medium M8 to feed medium M8 well.

[0119] In this way, the moving portion 421d is provided to be movable between a first position higher than the upper surface of the feed roller 112 and a second position lower than the upper surface of the feed roller 112 in the direction A12 perpendicular to the conveying surface 421a.

[0120] As described above in detail, the medium transport device is now able to appropriately feed a plurality of types of media even when the guide member 421 is provided to be movable.

[0121] FIG. 21(a) is a schematic diagram for explaining a feed arm 522 in a medium transport device according to yet another embodiment.

[0122] 21(a), the medium conveying device according to this embodiment has a feeding mechanism 520 instead of the feeding mechanism 120, and the feeding mechanism 520 has a feeding arm 522 instead of the feeding arm 122. The feeding arm 522 has a similar configuration to the feeding arm 122.

[0123] However, the feed arm 522 has a protrusion 522a, a pressure roller 522c, and a base 522e. The base 522e is fixed to the upper housing 102. The protrusion 522a and the pressure roller 522c have the same configurations as the protrusion 122a and the pressure roller 122c of the feed arm 122, respectively. However, the protrusion 522a is supported by the base 522e via a first elastic member 522h. The first elastic member 522h is a compression coil spring, rubber, or the like, and applies a downward force to the protrusion 522a. The pressure roller 522c is supported by the base 522e via a second elastic member 522i. The second elastic member 522i is a compression coil spring, rubber, or the like, and applies a downward force to the pressure roller 522c.

[0124] In this way, the pressure roller 522c is supported by the base portion 522e via the second elastic member 522i, which is separate from the first elastic member 522h provided between the base portion 522e and the protrusion 522a, so that the pressure roller 522c is provided to move independently of the protrusion 522a.

[0125] Generally, to properly transport a highly rigid medium such as cardboard, a greater transport force is required than to transport a less rigid medium. When the pressure roller moves in conjunction with the protrusions, when a highly rigid medium is transported, the protrusions are pushed up by the medium, causing the pressure roller to rise (float), reducing the force pressing against the medium and reducing the transport force. On the other hand, when the pressure roller 522c moves independently of the protrusions 522a, even if the protrusions 522a are pushed up by the highly rigid medium, the pressure roller 522c does not rise and continues to press the medium. Therefore, the medium transport device can properly transport highly rigid media such as cardboard while preventing jams from occurring when using a less rigid medium such as thin paper.

[0126] 21(a), the protrusion 522a may be located downstream of the pressure roller 522c in the medium conveying direction A1. If the pressure roller moves in conjunction with the protrusion, when a thin medium such as cardboard is conveyed after a thick medium, the protrusion may be pushed up by the rear end of the preceding medium, causing the pressure roller to rise and move away from the leading edge of the following medium. On the other hand, if the pressure roller 522c moves independently of the protrusion 522a, even if the protrusion 522a is pushed up by the preceding medium, the pressure roller 522c does not rise and continues to press the following medium. Therefore, the medium conveying device can feed each medium effectively even when multiple media of different thicknesses are fed continuously.

[0127] As described above in detail, the medium transport device is now able to appropriately feed a plurality of types of media even when the pressure roller 522c is arranged to move independently of the protrusion 522a.

[0128] FIG. 21B is a schematic diagram for explaining a feed arm 622 in a medium transport device according to yet another embodiment.

[0129] 21(b), the medium transport device according to this embodiment has a feeding mechanism 620 instead of the feeding mechanism 520, and the feeding mechanism 620 has a feeding arm 622 instead of the feeding arm 522. The feeding arm 622 has a similar configuration to the feeding arm 522.

[0130] However, the feed arm 622 has a protrusion 622a, a pressure roller 622c, and a base 622e. The base 622e is fixed to the upper housing 102. The protrusion 622a, the pressure roller 622c, and the base 622e have the same configurations as the protrusion 522a, the pressure roller 522c, and the base 522e of the feed arm 522, respectively. However, the protrusion 622a is supported by the base 622e via a first elastic member 622h. The first elastic member 622h is a compression coil spring, rubber, or the like, and applies a downward force to the protrusion 622a. The pressure roller 622c is supported by a member including the protrusion 622a via a second elastic member 622i. The second elastic member 622i is a compression coil spring, rubber, or the like, and applies a downward force to the pressure roller 622c.

[0131] In this case, too, the pressure roller 622c is arranged to move independently of the protrusion 622a. Therefore, the medium conveying device can effectively convey a highly rigid medium such as thick paper while preventing jamming of a less rigid medium such as thin paper. Furthermore, the medium conveying device can effectively convey each medium even when multiple media of different thicknesses are continuously fed.

[0132] As described above in detail, the medium transport device is now able to appropriately feed a plurality of types of media even when the pressure roller 622c is arranged to move independently of the protrusion 622a.

[0133] The feed arm 522 or the feed arm 622 may further have a second protrusion similar to the second protrusion 122d. In this case, the second protrusion is provided to move in conjunction with the protrusion 522a or the protrusion 622a, and to move independently of the pressure roller 522c or the pressure roller 622c.

[0134] FIG. 22 is a schematic diagram for explaining a guide member 721 in a medium conveyance device according to yet another embodiment.

[0135] 22, the medium transport device according to this embodiment has a feeding mechanism 720 instead of feeding mechanism 120, and feeding mechanism 720 has a guide member 721 instead of guide member 121. Guide member 721 has a configuration similar to that of guide member 121. Guide member 721 has an opening 721b similar to opening 121b, and transport surface 721a of guide member 721 has a recess 721c similar to recess 121c.

[0136] However, the opening 721b is smaller than the opening 121b, and the recess 721c extends in the width direction A8 up to the vicinity of the feed roller 112. Therefore, the protrusion 122a is disposed at a position facing the recess 721c.

[0137] As described above in detail, the medium transport device is now able to properly feed a plurality of types of media even when the protrusion 122a is positioned opposite the recess 721c.

[0138] FIG. 23 is a schematic diagram for explaining a guide member 821 in a medium conveyance device according to yet another embodiment.

[0139] 23, the medium conveying device according to this embodiment has a feeding mechanism 820 instead of the feeding mechanism 120, and the feeding mechanism 820 has a guide member 821 instead of the guide member 121. The guide member 821 has a configuration similar to that of the guide member 121. The conveying surface 821a of the guide member 821 has a recess 821c similar to the recess 121c.

[0140] However, the guide member 821 does not have the opening 121b, but instead has a notch 821b. The feed roller 112 is disposed within the notch 821b, and the protrusion 122a is disposed at a position facing the notch 821b.

[0141] As described above in detail, the medium transport device is now able to appropriately feed a plurality of types of media even when the guide member 821 has the notch 821b.

[0142] FIG. 24 is a schematic diagram for explaining a guide member 921 in a medium transport device according to yet another embodiment.

[0143] 24, the medium conveying device according to this embodiment has a feeding mechanism 920 instead of feeding mechanism 820, and feeding mechanism 920 has a guide member 921 instead of guide member 821. Guide member 921 has a configuration similar to guide member 821. Guide member 921 has a cutout portion 921b similar to cutout portion 821b, and conveying surface 921a of guide member 921 has a recess 921c similar to recess 821c.

[0144] However, the cutout portion 921b is smaller than the cutout portion 821b, and the recessed portion 921c extends in the width direction A8 up to the vicinity of the feed roller 112. Therefore, the protrusion portion 122a is disposed at a position facing the recessed portion 921c.

[0145] As described above in detail, the medium conveying device is now able to properly feed multiple types of media even when the guide member 921 has the cutout portion 921b and the protrusion portion 122a is positioned opposite the recess 921c.

[0146] 25 is a diagram showing a schematic configuration of a processing circuit 1050 in a medium conveying device according to yet another embodiment. The processing circuit 1050 is used in place of the processing circuit 150 of the medium conveying device 100, and executes medium reading processing and the like in place of the processing circuit 150. The processing circuit 1050 includes a control circuit 1051 and an image acquisition circuit 1052. Note that each of these components may be configured as an independent integrated circuit, microprocessor, firmware, or the like.

[0147] The control circuit 1051 is an example of a control unit, and has the same functions as the control unit 151. The control circuit 1051 receives an operation signal from the operation device 105 or the interface device 132, and a medium signal from the medium sensor 111. The control circuit 1051 controls the motor 131 based on the received information.

[0148] The image acquisition circuit 1052 is an example of an image acquisition unit, and has the same function as the image acquisition unit 152. The image acquisition circuit 1052 acquires an input image from the imaging device 116 and outputs it to the interface device 132.

[0149] As described above in detail, the medium conveying device is now able to appropriately feed multiple types of media even when using the processing circuit 1050. [Explanation of symbols]

[0150] 100 medium conveying device, 103 placing table, 112 feeding roller, 113 separation roller, 121, 421 guide member, 121a conveying surface, 121b opening, 121c, 421c recess, 121b, 721b opening, 122, 522, 622 feeding arm, 122a, 222a, 322a, 522a, 622a protrusion, 122b contact surface, 122c, 522c, 622c pressure roller, 122d second protrusion, 124 set guide, 421d moving portion, 821b, 921b notch portion

Claims

1. a guide member having an opening or a notch and forming a transport surface for the medium; a feed roller disposed within the opening or the notch and configured to feed a medium; a separation unit disposed opposite the feeding roller; protrusions disposed on the left and right of the separator in the medium transport direction; the protrusions are disposed at positions facing the openings or the notches, or the recesses of the guide members located on the left and right sides of the feed roller in the medium transport direction, a tip of the protrusion is located closer to the feed roller than a nip portion between the feed roller and the separation portion; A medium transport device characterized by:

2. The medium transport device according to claim 1 , wherein the protrusion is disposed at a position facing the opening, the notch, or the recess so that the medium is transported between the protrusion and the recess.

3. The medium transport device according to claim 1 or 2, wherein the protrusion is positioned so that at least a portion thereof overlaps with the nip portion and an area of ​​the feed roller upstream of the nip portion in the medium transport direction when viewed from a direction perpendicular to the medium transport direction.

4. A medium transport device as described in any one of claims 1 to 3, further comprising a pressure roller that faces the feed roller and is positioned upstream of the nip portion in the medium transport direction, and presses the medium fed by the feed roller toward the feed roller.

5. The medium transport device according to claim 4 , wherein the pressure roller is provided so as to move in conjunction with the protrusion.

6. The medium transport device according to claim 4 , wherein the pressure roller is provided so as to move independently of the protrusion.

7. A mounting table; a second guide member that is disposed at a first position to limit contact between the medium placed on the placement table and the feed roller and the pressure roller before the medium is fed, and that is disposed at a second position to allow contact between the medium placed on the placement table and the feed roller and the pressure roller during the medium feeding; A medium transport device as described in any one of claims 4 to 6, wherein when the second guide member moves from the first position to the second position, if the amount of media placed on the mounting table is equal to or greater than a predetermined amount, the pressure roller contacts the media placed on the mounting table before the feed roller, and if the amount of media placed on the mounting table is less than the predetermined amount, the pressure roller contacts the media placed on the mounting table after the feed roller.

8. A media transport device described in any one of claims 1 to 7, further having a second protrusion portion that faces the feed roller and is positioned upstream of the nip portion in the media transport direction, and that guides the media fed by the feed roller to the nip portion.

9. A medium transport device described in any one of claims 1 to 8, wherein the contact surface of the protrusion that comes into contact with the medium fed by the feed roller is formed so as to be parallel to the area upstream of the recess of the transport surface in the medium transport direction.

10. 10. The medium transport device according to claim 1, wherein a contact surface of the protrusion that comes into contact with the medium fed by the feed roller has an R-shape.

11. The medium transport device according to claim 1, wherein the protrusion has elasticity.

12. A medium transport device described in any one of claims 1 to 11, wherein the guide member is positioned outside the recess in a direction perpendicular to the medium transport direction, and further has a moving portion that is movable in a direction perpendicular to the transport surface depending on the weight of the medium being fed.

13. The medium transport device according to claim 12, wherein the moving portion is movable in a direction perpendicular to the transport surface between a first position higher than an upper surface of the feed roller and a second position lower than an upper surface of the feed roller.

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