Media transport device

Abstract

To provide a medium transport device that can suitably transport multiple media of different thicknesses from each other.SOLUTION: A medium transport device 100 comprises: a pair of transport rollers that include a first roller 114 and a second roller 115 that faces the upper side of the first roller, and transport a medium between the first roller and the second roller; a pair of guides that include a lower side guide 121 arranged on the upstream side in the medium transport direction with respect to the pair of transport rollers for guiding the medium to the pair of transport rollers, and an upper side guide 124 facing the lower side guide. The upper side guide is arranged so as to be movable upward in response to the transport of the medium, and the lower side guide is arranged so as to be movable downward in response to the transport of the medium, thereby the interval between the pair of guides can be changed according to the medium.SELECTED DRAWING: Figure 3A

Description

[Technical field]

[0001] The present invention relates to a media transport device, and more particularly to a media transport device having upper and lower guides that guide a medium to a transport roller. [Background technology]

[0002] In recent years, media transport devices such as scanners are required to transport media of various thicknesses, such as thin paper, plastic cards, passports, etc. In such media transport devices, when a thin medium such as thin paper is transported, the medium is likely to jam, while when a thick medium such as a plastic card or passport is transported, slippage is likely to occur between the transport roller and the medium.

[0003] A paper guide plate for an electrophotographic copying machine that feeds various types of copy paper to the nip between a pair of rollers that constitute a fixing device has been disclosed (see Patent Document 1). At the leading end of this paper guide plate, a step portion having a width approximately equal to the width of a small-sized thick paper is provided.

[0004] A media transport path is disclosed that has a transport roller, a pressure roller that faces the transport roller, and upper and lower guide plates that guide the transported media (see Patent Document 2). In this media transport path, a media guide body having a slope that guides the leading edge of the media toward the clamping portion between the transport roller and the pressure roller is provided upstream of the pressure roller in the transport direction, and at least the downstream side of this media guide body is displaceable. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Utility Model Application Publication No. 60-180247 [Patent Document 2] JP 2004-189371 A Summary of the Invention [Problem to be solved by the invention]

[0006] It is desirable for a media transport device to be able to properly transport a plurality of media each having a different thickness.

[0007] An object of the present invention is to provide a medium transport device capable of appropriately transporting a plurality of media each having a different thickness. [Means for solving the problem]

[0008] According to one aspect of the present invention, there is provided a medium transport device comprising: a transport roller pair including a first roller and a second roller facing the upper side of the first roller, transporting a medium between the first roller and the second roller; and a guide pair including a lower guide disposed upstream of the transport roller pair in a medium transport direction in order to guide the medium to the transport roller pair, and an upper guide facing the lower guide. The medium conveying device has a swinging section that swings in response to the conveyance of the medium, and in the medium conveying direction, an upstream end of the swinging section is located upstream of an upstream end of the second roller, and a downstream end of the swinging section is located downstream of an upstream end of the second roller, and when the medium is not being conveyed, the downstream end of the swinging section is disposed so as to be located lower than the upstream end, and the swinging section swings in response to the thickness of the medium being conveyed. . A media transport device according to one aspect of the present invention has a transport roller pair including a first roller and a second roller facing the upper side of the first roller, transporting a medium between the first roller and the second roller, and a guide pair including a lower guide arranged upstream of the transport roller pair in the media transport direction to guide the medium to the transport roller pair, and an upper guide facing the lower guide, wherein the upper guide has a fixed part that guides the medium, and a oscillating part connected to the downstream side of the fixed part in the media transport direction and oscillating in response to the transport of the medium, wherein in the media transport direction, the upstream end of the oscillating part is located upstream of the upstream end of the second roller, and the downstream end of the oscillating part is located downstream of the upstream end of the second roller, and when the medium is not being transported, the downstream end of the oscillating part is arranged to be located lower than the upstream end, and the oscillating part oscillates in response to the thickness of the medium being transported. Effect of the Invention

[0009] According to the present invention, the medium transport device is capable of appropriately transporting a plurality of media each having a different thickness. [Brief description of the drawings]

[0010] [Figure 1] 1 is a perspective view showing a medium conveying device 100 according to an embodiment. [Diagram 2] 2 is a diagram for explaining a transport path inside the medium transport device 100. FIG. [Figure 3A] 13 is a schematic diagram for explaining a first lower guide 121 and the like. FIG. [Figure 3B] 13 is a schematic diagram for explaining a first lower guide 121 and the like. FIG. [Figure 4] FIG. 11 is a schematic diagram for explaining a first moving part 121a. [Figure 5A]11 is a schematic diagram for explaining the operation of a first moving part 121a and the like. FIG. [Figure 5B] 11 is a schematic diagram for explaining the operation of a first moving part 121a and the like. FIG. [Figure 6A] 11 is a schematic diagram for explaining the operation of a first moving part 121a and the like. FIG. [Figure 6B] 11 is a schematic diagram for explaining the operation of a first moving part 121a and the like. FIG. [Figure 7A] 10A and 10B are schematic diagrams for explaining the relationship between a medium transport force and a transport load. [Figure 7B] 7 is a graph 700 illustrating the force on the media versus the outer diameter of the roller. [Figure 8] 13 is a schematic diagram for explaining another first lower guide 221. FIG. [Figure 9A] 13 is a schematic diagram for explaining another second conveyor roller 215. FIG. [Figure 9B] 13 is a schematic diagram for explaining another second conveyor roller 215. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Hereinafter, a medium conveying device according to one aspect of the present invention will be described with reference to the drawings. However, it should be noted that the technical scope of the present invention is not limited to the embodiment, but extends to the inventions described in the claims and their equivalents.

[0012] FIG. 1 is a perspective view showing a medium conveying device 100 configured as an image scanner. The medium conveying device 100 conveys a medium, which is an original, and captures an image. The medium is a thick medium (e.g., a medium having a thickness of more than 2 mm) such as paper such as thin paper, cardboard, plastic cards, booklets, or passports. In other words, the media supported by the medium conveying device 100 include a plurality of media each having a different thickness. The medium conveying device 100 may be a facsimile, a copier, a multifunction printer (MFP, Multifunction Peripheral), or the like. Note that the medium to be conveyed may not be an original but may be a print target, and the medium conveying device 100 may be a printer, or the like.

[0013] The medium conveying device 100 includes a lower housing 101, an upper housing 102, a placement table 103, and a discharge table 104.

[0014] The upper housing 102 is disposed in a position that covers the top surface of the medium conveying device 100, and engages with the lower housing 101 by a hinge so that it can be opened and closed when a medium is jammed, when the inside of the medium conveying device 100 is cleaned, and the like.

[0015] The placement stage 103 is engaged with the lower housing 101 so that the medium to be transported can be placed thereon. The ejection stage 104 is engaged with the lower housing 101 so that the ejected medium can be held thereon.

[0016] FIG. 2 is a diagram for explaining a transport path inside the medium transport device 100. As shown in FIG.

[0017] The transport path inside the medium transport device 100 includes a feed roller 111, a brake roller 112, a sensor 113, a first transport roller 114, a second transport roller 115, a first imaging device 116a, a second imaging device 116b, a third transport roller 117, and a fourth transport roller 118. The number of each roller is not limited to one, and each roller may be provided in multiple numbers. In FIG. 2, an arrow A1 indicates the medium transport direction. In the following, 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.

[0018] The upper surface of the lower housing 101 forms a first lower guide 121, a second lower guide 122, and a third lower guide 123 which form the lower surface of the medium transport path. Meanwhile, the lower surface of the upper housing 102 forms a first upper guide 124, a second upper guide 125, and a third upper guide 126 which form the upper surface of the medium transport path.

[0019] The first lower guide 121 is an example of a lower guide, and is disposed upstream of the first transport roller 114 and the second transport roller 115 in the medium transport direction A1, and guides the medium to the first transport roller 114 and the second transport roller 115. The second lower guide 122 includes an area corresponding to the first transport roller 114 and the second transport roller 115 in the medium transport direction A1, and is disposed downstream of the first lower guide 121 and upstream of the first imaging device 116a and the second imaging device 116b. The second lower guide 122 guides the medium to the first imaging device 116a and the second imaging device 116b. The third lower guide 123 is disposed downstream of the first imaging device 116a and the second imaging device 116b, and guides the medium to the discharge tray 104. The first lower guide 121, the second lower guide 122, and the third lower guide 123 are each formed of a separate member. The first lower guide 121, the second lower guide 122 and the third lower guide 123 may be formed from a single member.

[0020] The first upper guide 124 is an example of an upper guide, and is disposed at a position opposite to the first lower guide 121, and guides the medium to the first conveying roller 114 and the second conveying roller 115. The second upper guide 125 is disposed at a position opposite to the second lower guide 122, and guides the medium to the first imaging device 116a and the second imaging device 116b. The third upper guide 126 is disposed at a position opposite to the third lower guide 123, and guides the medium to the discharge tray 104. The first upper guide 124, the second upper guide 125, and the third upper guide 126 are each formed of separate members. It should be noted that the first upper guide 124, the second upper guide 125, and the third upper guide 126 may be formed of a single member.

[0021] The feed roller 111 is provided in the lower housing 101, and feeds the media placed on the placement table 103 from the bottom up. The brake roller 112 is provided in the upper housing 102, and is disposed opposite the feed roller 111.

[0022] The sensor 113 is disposed downstream of the feed roller 111 and the brake roller 112 and upstream of the first conveyor roller 114 and the second conveyor roller 115 in the medium conveying direction A1. The sensor 113 detects whether a medium is present at that position and detects a medium passing between the feed roller 111 and the brake roller 112 and the first conveyor roller 114 and the second conveyor roller 115. The sensor 113 includes a light emitter and a light receiver provided on one side of the medium conveying path, and a reflecting member such as a mirror provided at a position facing the light emitter and the light receiver across the conveying path. The light emitter irradiates light toward the conveying path. On the other hand, the light receiver receives the light irradiated by the light emitter and reflected by the reflecting member, and generates and outputs a medium signal, which is an electrical signal according to the intensity of the received light. When a medium is present at the position of the sensor 113, the light irradiated by the light emitter is blocked by the medium, so the signal value of the medium signal changes depending on whether a medium is present at the position of the sensor 113 or not. The light emitter and the light receiver may be provided at positions facing each other across the transport path, and the reflecting member may be omitted.

[0023] The first conveying roller 114 is an example of a first roller, and is provided in the lower housing 101. The second conveying roller 115 is an example of a second roller, and is provided in the upper housing 102, and is disposed facing the upper side of the first conveying roller 114. The first conveying roller 114 and the second conveying roller 115 are disposed downstream of the feed roller 111 and the brake roller 112 in the medium conveying direction A1. The first conveying roller 114 and the second conveying roller 115 are an example of a conveying roller pair, and convey the medium fed by the feed roller 111 and the brake roller 112 downstream between the first conveying roller 114 and the second conveying roller 115.

[0024] The first imaging device 116a has a line sensor using a CIS (Contact Image Sensor) of a life-size optical system type having imaging elements using CMOS (Complementary Metal Oxide Semiconductor) linearly arranged in the main scanning direction. The first imaging device 116a also has a lens that forms an image on the imaging elements, and an A / D converter that amplifies and analog-to-digital (A / D) converts the electrical signal output from the imaging elements. The first imaging device 116a generates and outputs an input image by capturing an image of the surface of the transported medium under the control of a processing circuit (not shown).

[0025] Similarly, the second imaging device 116b has a line sensor using a CIS of a life-size optical system type having CMOS imaging elements arranged in a line 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 generates and outputs an input image by imaging the back side of the transported medium according to control from the processing circuit.

[0026] The medium conveying device 100 may have only one of the first imaging device 116a and the second imaging device 116b arranged to read only one side of the medium. Also, instead of a CIS line sensor of an equal magnification optical system type having a CMOS imaging element, a CIS line sensor of an equal magnification optical system type having a CCD (Charge Coupled Device) imaging element may be used. Also, a reduction optical system type line sensor having a CMOS or CCD imaging element may be used.

[0027] The third transport roller 117 is provided in the lower housing 101. The fourth transport roller 118 is provided in the upper housing 102, and is disposed facing the upper side of the third transport roller 117. The third transport roller 117 and the fourth transport roller 118 are disposed downstream in the medium transport direction A1 relative to the first transport roller 114 and the second transport roller 115. The third transport roller 117 and the fourth transport roller 118 transport the medium transported by the first transport roller 114 and the second transport roller 115 further downstream between the third transport roller 117 and the fourth transport roller 118.

[0028] The medium placed on the mounting table 103 is transported between the first lower guide 121 and the first upper guide 124 in the medium transport direction A1 by the feed roller 111 rotating in the direction of the arrow A2 in Fig. 2, i.e., the medium feed direction. The brake roller 112 rotates in the direction of the arrow A3, i.e., the opposite direction to the medium feed direction, when transporting the medium. When multiple media are placed on the mounting table 103, the feed roller 111 and the brake roller 112 function to separate only the media placed on the mounting table 103 that is in contact with the feed roller 111. This operates to restrict the transport of media other than the separated media (preventing double feeding).

[0029] The medium is fed between the first conveyor roller 114 and the second conveyor roller 115 while being guided by the first lower guide 121 and the first upper guide 124. The medium is fed between the first imaging device 116a and the second imaging device 116b while being guided by the second lower guide 122 and the second upper guide 125 as the first conveyor roller 114 and the second conveyor roller 115 rotate in the directions of the arrows A4 and A5, respectively. The medium is read by the first imaging device 116a and the second imaging device 116b. Thereafter, the medium is discharged onto the discharge tray 104 while being guided by the third lower guide 123 and the third upper guide 126 as the third conveyor roller 117 and the fourth conveyor roller 118 rotate in the directions of the arrows A6 and A7, respectively.

[0030] 3A and 3B are schematic diagrams for explaining the first lower guide 121 and the first upper guide 124. Fig. 3A is a schematic diagram showing a state in which the first lower guide 121 and the first upper guide 124 are arranged at a first position, which is an initial position. Fig. 3B is a schematic diagram showing a state in which the first lower guide 121 and the first upper guide 124 are arranged at a second position, which is the lowest and highest position, respectively.

[0031] 3A and 3B, a compression coil spring 115a is provided between the upper housing 102 and a shaft which is a rotation axis of the second conveyor roller 115. The second conveyor roller 115 is provided so as to be movable upward by the medium being conveyed, and the compression coil spring 115a is provided so as to apply a force downward to the second conveyor roller 115, i.e., toward the first conveyor roller 114 side.

[0032] The first lower guide 121 includes a first moving portion 121a, a first supporting portion 121b, and a recess 121c. The first moving portion 121a is an example of a moving portion and is formed of a flexible member. The first supporting portion 121b is an example of a supporting portion and supports the upstream end of the first moving portion 121a at its downstream end. The recess 121c faces the first moving portion 121a and is provided at a position below the first moving portion 121a. The first supporting portion 121b and the recess 121c allow the first moving portion 121a to move (swing) downward (in the direction of the arrow A8). The first moving portion 121a and the first supporting portion 121b are formed of separate members. The first moving portion 121a and the first supporting portion 121b may be formed of a single member.

[0033] The first upper guide 124 includes a second moving part 124a and a second support part 124b. The second moving part 124a has a protrusion 124c at an upstream end, and the second support part 124b has a recess at a downstream end. The tip of the protrusion 124c of the second moving part 124a is engaged with the recess of the second support part 124b, so that the second support part 124b supports the second moving part 124a rotatably (swingably) at the downstream end. In addition, a torsion coil spring 124d is provided between the second moving part 124a and the second support part 124b. The torsion coil spring 124d is provided around the protrusion 124c so as to apply a force downward (opposite to the arrow A9) to the second moving part 124a. The second moving part 124a is stopped by a stopper (not shown) so as not to move downward from the first position shown in FIG. 3A. The second moving portion 124a is provided so as to be movable (swingable) upward (in the direction of arrow A9) by the second supporting portion 124b and the torsion coil spring 124d.

[0034] The second moving portion 124a and the second supporting portion 124b are formed of separate members. The second moving portion 124a and the second supporting portion 124b may be formed of a single member. Also, instead of the torsion coil spring 124d, a compression coil spring or a rubber member that presses the second moving portion 124a downward may be used.

[0035] 3A, in the height direction A10 perpendicular to the first lower guide 121 and the first upper guide 124, the first conveyor roller 114 is provided so as to protrude upward relative to the first moving part 121a arranged at the first position. This allows the first lower guide 121 to convey the medium so as to reliably contact the first conveyor roller 114, and allows the first conveyor roller 114 to convey the medium appropriately. However, if the protruding amount Y1 of the first conveyor roller 114 is too large, the leading edge of the medium may collide with the first conveyor roller 114 at a substantially right angle, which may cause the medium to jam. For this reason, it is preferable that the protruding amount Y1 of the first conveyor roller 114 is as small as possible.

[0036] The protrusion amount Y1 of the first conveyor roller 114 is set within a range of, for example, 0.5 mm to 1.0 mm inclusive. The protrusion amount Y1 is the distance in the height direction A10 from the downstream end of the first moving part 121a arranged at the first position to the upper end of the first conveyor roller 114 (the nip portion between the first conveyor roller 114 and the second conveyor roller 115).

[0037] Similarly, in the height direction A10, the second conveying roller 115 is provided so as to protrude downward from the second moving part 124a arranged at the first position. This allows the first upper guide 124 to reliably convey the medium to the nip part between the first conveying roller 114 and the second conveying roller 115 even if the medium is bent and floats upward, and the first conveying roller 114 and the second conveying roller 115 can appropriately convey the medium. However, if the protruding amount X1 of the second conveying roller 115 is too large, the leading edge of the medium that has been bent and floats upward may collide with the second conveying roller 115 at a substantially right angle, which may cause a medium jam. For this reason, it is preferable that the protruding amount X1 of the second conveying roller 115 is as small as possible.

[0038] The protrusion amount X1 of the second conveyor roller 115 is set within a range of, for example, 0.1 mm to 1.0 mm. The protrusion amount X1 is the distance in the height direction A10 from the downstream end of the second moving part 124a arranged at the first position to the upper end of the first conveyor roller 114.

[0039] On the other hand, as shown in FIG. 3B, in the height direction A10, the first conveying roller 114 is provided so as to protrude upward from the first moving part 121a arranged at the second position more than when the first moving part 121a is arranged at the first position. When a thick medium such as a plastic card or passport is conveyed, if the contact area between the medium and the first conveying roller 114 is too small, the conveying force of the first conveying roller 114 on the medium becomes small, and the medium may slip and not be conveyed well. Therefore, it is preferable that the protruding amount Y2 of the first conveying roller 114 with respect to the first moving part 121a arranged at the second position is somewhat large. However, if the protruding amount Y2 of the first conveying roller 114 is too large, the leading edge of the medium may collide with the first conveying roller 114 at a substantially right angle, causing a medium jam.

[0040] The protrusion amount Y2 of the first conveying roller 114 is set within a range of, for example, 1 / 3 or more of the maximum thickness of the medium supported by the medium conveying device 100 and 1 / 2 or less of the roller diameter of the first conveying roller 114. More preferably, the protrusion amount Y2 is set to 1 / 2 or more of the maximum thickness of the medium supported by the medium conveying device 100. For example, if the maximum thickness of the medium supported by the medium conveying device 100 is 7 mm and the roller diameter of the first conveying roller 114 is 16 mm, the protrusion amount Y2 is set within a range of 2.3 mm or more and 8 mm or less (more preferably 3.5 mm). The protrusion amount Y2 is the distance in the height direction A10 from the downstream end of the first moving part 121a arranged at the second position to the upper end of the first conveying roller 114. That is, the protrusion amount Y1 and the protrusion amount Y2 are the distance in the height direction A10 from the position where the lower end of the conveyed medium abuts against the first conveying roller 114 to the upper end of the first conveying roller 114.

[0041] In addition, in the height direction A10, the second conveying roller 115 is provided so as to protrude downward from the second moving part 124a arranged at the second position more than when the second moving part 124a is arranged at the first position. When a thick medium such as a plastic card or passport is conveyed, if the contact area between the medium and the second conveying roller 115 is too small, the conveying force of the second conveying roller 115 on the medium becomes small, and the medium may slip and not be conveyed well. Therefore, it is preferable that the protruding amount X2 of the second conveying roller 115 with respect to the second moving part 124a arranged at the second position is somewhat large. However, if the protruding amount X2 of the second conveying roller 115 is too large, the leading edge of the medium may collide with the second conveying roller 115 at a substantially right angle, causing a medium jam.

[0042] The protrusion amount X2 of the second conveying roller 115 is set within a range of, for example, the maximum thickness of the medium supported by the medium conveying device 100 or more and 3 / 2 or less of the maximum thickness. In addition, it is preferable that the protrusion amount X2 is set to 2 / 3 or less of the roller diameter of the second conveying roller 115. For example, if the maximum thickness of the medium supported by the medium conveying device 100 is 7 mm, the protrusion amount X2 is set within a range of 7 mm or more and 10.5 mm or less (for example, 10 mm). The protrusion amount X2 is the distance in the height direction A10 from the downstream end of the second moving part 124a arranged at the second position to the upper end of the first conveying roller 114. In other words, the protrusion amount X1 and the protrusion amount X2 are the distance in the height direction A10 from the position where the upper end of the medium guided by the first upper guide 124 abuts against the second conveying roller 115 to the upper end of the first conveying roller 114.

[0043] The distance H in the height direction A10 between the first moving part 121a and the second moving part 124a arranged at the second position is the sum of the protrusion amount Y2 and the protrusion amount X2, and is set within the range of 9.3 mm or more and 22 mm or less (more preferably 13.5 mm).

[0044] In this way, in the medium conveying device 100, the first upper guide 124 (second moving section 124a) is arranged so as to be movable upward in response to the conveyance of the medium, and the first lower guide 121 (first moving section 121a) is arranged so as to be movable downward in response to the conveyance of the medium. This allows the distance between the first upper guide 124 and the first lower guide 121 to be changed in response to the medium. Also, by changing the distance between the first upper guide 124 and the first lower guide 121, the distance (protrusion amount Y1 and protrusion amount Y2) from the position where the lower end of the medium abuts against the first conveying roller 114 to the upper end of the first conveying roller 114 is changed.

[0045] Fig. 4 is a schematic diagram for explaining the first moving part 121a. Fig. 4 is a schematic diagram of the lower housing 101 viewed from above with the upper housing 102 removed.

[0046] 4, the first lower guide 121 is disposed upstream of the first transport roller 114 and the second transport roller 115 in the medium transport direction A1. The first support portion 121b is formed downstream of the feed roller 111 and the brake roller 112 in the medium transport direction A1. The first moving portion 121a is disposed between the first support portion 121b and the first transport roller 114 and the second transport roller 115 in the medium transport direction A1.

[0047] The first lower guide 121 is formed across both ends of the medium transport path in the width direction A11 perpendicular to the medium transport direction. The first moving part 121a is disposed in the approximate center of the medium transport path in the width direction A11. In general, the size in the width direction A11 of a thick medium transported by the medium transport device, such as a plastic card or passport, is smaller than the size in the width direction A11 of a commonly used paper such as A4 paper. The first moving part 121a is disposed only in the center, not across both ends of the medium transport path, so that it moves when a thick medium is transported but does not move when a commonly used paper is transported. This allows the medium transport device 100 to suppress the occurrence of a medium jam when a commonly used paper is transported.

[0048] Furthermore, two slits 121d are formed in the first moving part 121a at positions at a predetermined distance from both ends in the width direction A11. This makes the first moving part 121a more flexible when a thick medium passes through it, allowing the thick medium to be transported well. In particular, the first moving part 121a is more flexible when the medium passes between the two slits 121d. Therefore, it is preferable that the distance between the two slits 121d is set to a length that is equal to the length of the plastic card or passport in the width direction A11 plus a margin.

[0049] 4, three sensors 113 are provided. The medium conveying device 100 determines whether a medium jam has occurred according to the timing at which the medium passed through the sensor 113. The medium conveying device 100 also determines whether a medium skew has occurred by comparing the timing at which the medium passed through the three sensors 113. The first moving section 121a has an opening at a position facing the light emitter 113a and the light receiver 113b of each sensor 113. This allows each sensor 113 to properly detect the medium.

[0050] 5A, 5B, 6A, and 6B are schematic diagrams for explaining the operation of the first moving section 121a and the second moving section 124a when a medium is transported. FIG. 5A is a diagram showing the first moving section 121a and the second moving section 124a when a paper sheet P is transported as a medium. FIG. 5B is a diagram showing the first moving section 121a and the second moving section 124a when a paper sheet P is transported as a medium and the paper sheet P is bent upward and lifted. FIG. 6A is a diagram showing the first moving section 121a and the second moving section 124a when a plastic card C is transported as a medium. FIG. 6B is a diagram showing the first moving section 121a and the second moving section 124a when a plastic card C is transported as a medium and the card C is transported to the nip portion between the feed roller 111 and the brake roller 112.

[0051] 5A, when paper P is transported as the medium, the first moving section 121a and the second moving section 124a do not move from the first position. As a result, the first moving section 121a brings the medium into contact with the first transport roller 114 and guides it to the nip between the first transport roller 114 and the second transport roller 115. Because the protrusion amount Y1 of the first transport roller 114 is sufficiently small, the transported medium is unlikely to collide with the first transport roller 114 at a substantially right angle, causing a jam.

[0052] 5B, when paper P is transported as a medium and the paper P bends upward and floats up, the first moving section 121a and the second moving section 124a do not move from the first position. As a result, the second moving section 124a brings the medium that has floated upward into contact with the second transport roller 115 or the first transport roller 114, and guides it to the nip between the first transport roller 114 and the second transport roller 115. Because the protrusion amount X1 of the second transport roller 115 is sufficiently small, the transported medium is unlikely to collide with the second transport roller 115 at a substantially right angle, causing a jam.

[0053] As shown in FIG. 6A, when a card C is transported as a medium, the first moving section 121a moves downward from the first position due to the weight of the card C. As a result, the first moving section 121a guides the medium to the first transport roller 114 so that the contact area between the medium and the first transport roller 114 becomes sufficiently large. As a result, the frictional force between the first transport roller 114 and the medium increases, and the first transport roller 114 can transport the medium with sufficient transport force. Furthermore, as the first moving section 121a moves downward, the card C comes into contact with the second transport roller 115 from below. As a result, the second transport roller 115 is pushed up more effectively by the card C.

[0054] As shown in FIG. 6B, when the upper part of the card C conveyed by the first conveying roller 114 comes into contact with the second moving part 124a, the second moving part 124a is pushed up by the thickness of the card C and moves upward from the first position. As a result, the second moving part 124a guides the medium to the second conveying roller 115 so that the area of ​​contact between the medium and the second conveying roller 115 becomes sufficiently large. In addition, as the second moving part 124a moves upward, the card C is sandwiched between the first moving part 121a and the second moving part 124a so as to be pressed, and the frictional force between the card C and the second moving part 124a is prevented from becoming too large. As a result, the frictional force between the second conveying roller 115 and the medium becomes large and the frictional force between the medium and the second moving part 124a becomes small, so that the medium is conveyed well.

[0055] FIG. 7A is a schematic diagram for explaining the relationship between the medium transport force and the transport load.

[0056] 7A, a first conveying force F1 is applied to the medium M in the medium conveying direction A1 in response to the frictional force between the medium M and the feed roller 111 and the brake roller 112, and the pressing force of the compression coil spring 112a pressing the brake roller 112 toward the feed roller 111. In addition, a second conveying force F2 is applied to the medium M in response to the frictional force between the medium M and the first conveying roller 114 and the second conveying roller 115, and the pressing force of the compression coil spring 115a pressing the second conveying roller 115 toward the first conveying roller 114.

[0057] Meanwhile, a first load L1 corresponding to a force for separating the medium by the brake roller 112 rotating in the direction A3 opposite to the medium feeding direction is applied to the medium M in the direction opposite to the medium transport direction A1. A second load L2 corresponding to a frictional force generated by the first lower guide 121 and the first upper guide 124 coming into contact with the medium M is applied to the medium M in the direction opposite to the medium transport direction A1. A third load L3 received when the second transport roller 115 is pushed upward is applied to the medium M in the direction opposite to the medium transport direction A1.

[0058] When the sum of the first conveying force F1 and the second conveying force F2 is greater than the sum of the first load L1, the second load L2, and the third load L3, the medium M is conveyed in the medium conveying direction A1. However, when the second conveying force F2 is sufficiently small relative to the first conveying force F1, or when the second load L2 and / or the third load L3 are sufficiently large relative to the first conveying force F1, the medium M may buckle and cause a medium jam.

[0059] As described above, the first moving part 121a moves downward due to the weight of the medium M, and the second moving part 124a moves upward due to the thickness of the medium M. Therefore, when a medium having a certain weight and thickness is transported, the contact area between the first transport roller 114 and the second transport roller 115 and the medium M becomes large, and the second transport force F2 corresponding to the frictional force between the first transport roller 114 and the second transport roller 115 and the medium M becomes large.

[0060] In this case, the force with which the medium M is pressed by the first moving part 121a and the second moving part 124a becomes smaller, and the second load L2 corresponding to the frictional force generated by the first lower guide 121 and the first upper guide 124 coming into contact with the medium M becomes smaller.

[0061] Furthermore, the medium M contacts the second transport roller 115 from the side and pushes up the second transport roller 115, and the lower the position at which the medium M contacts the second transport roller 115, the smaller the force with which the medium M can push up the second transport roller 115. Since the first moving portion 121a moves downward due to the weight of the medium M, the medium M can push up the second transport roller 115 from further below, and the third load L3 received when pushing the second transport roller 115 upward becomes smaller.

[0062] Therefore, by providing the first moving part 121a and the second moving part 124a so that they can be moved by the thick medium, the medium conveying device 100 can satisfactorily convey the thick medium.

[0063] FIG. 7B is a graph 700 illustrating the force exerted by a roller on a media versus the outer diameter of the roller.

[0064] The horizontal axis of the graph 700 shown in FIG. 7B indicates the size of the outer diameter of the roller, and the vertical axis indicates the ratio of the sum of the first conveying force F1 and the second conveying force F2 to the sum of the first load L1, the second load L2, and the third load L3. Graph 701 indicates the ratio when both the first conveying roller 114 and the second conveying roller 115 are rotated, and graph 702 indicates the ratio when only one of the first conveying roller 114 and the second conveying roller 115 is rotated. In the graph 700, when the ratio is equal to or greater than the threshold value T, the medium is stably conveyed, but when the ratio is less than the threshold value T, the medium may not be stably conveyed. Therefore, when both the first conveying roller 114 and the second conveying roller 115 are rotated, the outer diameter of each conveying roller needs to be equal to or greater than D1. Also, when only one of the first conveying roller 114 and the second conveying roller 115 is rotated, the outer diameter of each conveying roller needs to be equal to or greater than D2.

[0065] That is, by increasing the outer diameter of the first transport roller 114 and the second transport roller 115, it is possible to increase the ratio of the transport force to the load, and the medium can be transported well. However, increasing the outer diameter of the first transport roller 114 and the second transport roller 115 increases the size and weight of the medium transport device 100. By providing the first moving part 121a and the second moving part 124a so that they can be moved by a thick medium, the medium transport device 100 can transport the medium well without increasing the size and weight of the medium transport device 100.

[0066] The ratio of the conveying force to the load by the roller changes not only depending on the outer diameter of the roller but also on the material of the roller (rubber hardness or friction between the roller and the medium, etc.). However, limiting the material of the roller may increase the cost of the medium conveying device 100. By providing the first moving part 121a and the second moving part 124a to be movable by a thick medium, the medium conveying device 100 can convey the medium well even if the roller material is not optimal.

[0067] As described above in detail, the medium conveying device 100 controls the protrusion amount of the conveying roller by vertically moving the guide pairs provided above and below the conveying path. In this way, the medium conveying device 100 can obtain sufficient conveying force when a thick medium is conveyed, and can appropriately guide the medium to prevent jamming when a thin paper is conveyed. Therefore, the medium conveying device 100 can appropriately convey a plurality of media each having a different thickness.

[0068] Furthermore, when transporting thick media, the user no longer needs to store the media in a special sheet or the like before transporting it, and the media transporting device 100 has made it possible to improve user convenience.

[0069] FIG. 8 is a schematic diagram for explaining a first lower guide 221 in a medium conveying device according to another embodiment.

[0070] As shown in FIG. 8, the medium conveying device according to this embodiment has a first lower guide 221 instead of the first lower guide 121. The first lower guide 221 is an example of a lower guide and includes a first moving portion 221a, a first support portion 221b, and a recess 221c. The first moving portion 221a is an example of a moving portion, is formed of a resin member or a metal member, and has a protrusion 221d at an upstream end. The first support portion 221b is an example of a support portion, and has a recess at a downstream end. The tip of the protrusion 221d of the first moving portion 221a engages with the recess of the first support portion 221b, so that the first support portion 221b rotatably (swingably) supports the first moving portion 221a at the downstream end.

[0071] In addition, a torsion coil spring 221e is provided between the first moving part 221a and the first support part 221b. The torsion coil spring 221e is provided around the protrusion part 221d so as to apply a force to the first moving part 221a in the upward direction (opposite to the direction of the arrow A8). The torsion coil spring 221e is an example of a pressing member, and presses the first lower guide 221 upward. The first moving part 221a is stopped by a stopper (not shown) so as not to move upward from the first position shown in FIG. 8. In addition, the recess 221c is provided at a position opposite to the first moving part 221a and below the first moving part 221a. The first support part 221b, the recess 221c, and the torsion coil spring 221e allow the first moving part 221a to move (swing) downward (in the direction of the arrow A8).

[0072] As described above in detail, the medium transport device is able to appropriately transport a plurality of media each having a different thickness, even when the first moving portion 221a is provided movably using a pressing member.

[0073] Instead of the torsion coil spring 221e, a compression coil spring or a rubber member may be used as the pressing member. In that case, the compression coil spring or the rubber member is provided between the first moving part 221a and the recess 221c so as to press the first moving part 221a upward. Also, the pressing member may be omitted and the first moving part itself may be formed of an elastic member such as rubber.

[0074] 9A and 9B are schematic diagrams for explaining a second conveyance roller 215 in a medium conveyance device according to yet another embodiment.

[0075] 9A and 9B, the medium conveying device according to this embodiment has a second conveying roller 215 instead of the second conveying roller 115. The second conveying roller 215 is disposed shifted downstream in the medium conveying direction A1 (toward the first imaging device 116a and the second imaging device 116b) with respect to the first conveying roller 114.

[0076] The protrusion amount Y1, the protrusion amount Y2, and the protrusion amount X1 in the medium conveying device of this embodiment are set within the same range as the protrusion amount Y1, the protrusion amount Y2, and the protrusion amount X1 in the medium conveying device 100. Note that the protrusion amount X1 in the medium conveying device of this embodiment is the distance in the height direction A10 from the downstream end of the second moving part 124a arranged at the first position to the upper end of the first conveying roller 114, similar to the protrusion amount X1 in the medium conveying device 100.

[0077] On the other hand, the protrusion amount X2' in the medium conveying device of this embodiment is set to a value smaller than the protrusion amount X2 in the medium conveying device 100. The protrusion amount X2' in the medium conveying device of this embodiment is the distance in the height direction A10 from the downstream end of the second moving part 124a arranged at the second position to the upper end of the first conveying roller 114, similar to the protrusion amount X2 in the medium conveying device 100. For example, when the second conveying roller 215 is arranged with a shift of 1 mm with respect to the first conveying roller 114, the protrusion amount X2' is set within a range of 2 / 3 or more and 4 / 3 or less of the maximum thickness of the medium supported by the medium conveying device. In addition, it is preferable that the protrusion amount X2' is set to 2 / 3 or less of the roller diameter of the second conveying roller 215. For example, when the maximum thickness of the medium supported by the medium conveying device 100 is 7 mm, the protrusion amount X2' is set within a range of 4.7 mm or more and 9.3 mm or less (for example, 7 mm).

[0078] The distance H' in the height direction A10 between the first moving part 121a and the second moving part 124a arranged at the second position is the sum of the protrusion amount Y2 and the protrusion amount X2', and is set within the range of 7.0 mm or more and 17.3 mm or less (more preferably 10.5 mm).

[0079] When the second transport roller 215 is positioned downstream in the medium transport direction A1 relative to the first transport roller 114, the medium is transported so as to ride up onto the first transport roller 114, increasing the area of ​​contact between the medium and the first transport roller 114. This increases the frictional force between the first transport roller 114 and the medium, allowing the first transport roller 114 to transport the medium with sufficient transport force. Therefore, the medium transport device can transport the medium well even if the protrusion amount X2' and the distance H' are smaller than the protrusion amount X2 and the distance H.

[0080] As described above in detail, the media conveying device is now capable of properly conveying multiple media each having different thicknesses, even when the second conveying roller 215 is positioned offset downstream in the media conveying direction A1 relative to the first conveying roller 114. [Explanation of symbols]

[0081] 100 medium conveying device, 114 first conveying roller, 115 second conveying roller, 121 first lower guide, 121a first moving portion, 121b first support portion, 124 first upper guide, 221e torsion coil spring

Claims

1. a conveying roller pair including a first roller and a second roller facing an upper side of the first roller, the conveying roller pair conveying a medium between the first roller and the second roller; a guide pair including a lower guide disposed upstream of the pair of transport rollers in a media transport direction and an upper guide opposed to the lower guide in order to guide the medium to the pair of transport rollers; the upper guide has a swinging portion that swings in response to transport of the medium, In a medium transport direction, an upstream end of the swinging portion is located upstream of an upstream end of the second roller, and a downstream end of the swinging portion is located downstream of an upstream end of the second roller, When the medium is not being transported, the downstream end of the swinging portion is disposed so as to be located lower than the upstream end thereof, The swinging portion swings in accordance with the thickness of the medium being transported. A medium transport device comprising:

2. The upper guide further has a fixing portion, The medium transport device according to claim 1 , wherein the swinging portion is connected to a downstream side of the fixed portion in a medium transport direction.

3. a conveying roller pair including a first roller and a second roller facing an upper side of the first roller, the conveying roller pair conveying a medium between the first roller and the second roller; a guide pair including a lower guide disposed upstream of the pair of transport rollers in a media transport direction and an upper guide opposed to the lower guide in order to guide the medium to the pair of transport rollers; the upper guide has a fixed portion that guides the medium, and a swinging portion that is connected to the fixed portion on the downstream side in the medium transport direction and swings in response to transport of the medium, In a medium transport direction, an upstream end of the swinging portion is located upstream of an upstream end of the second roller, and a downstream end of the swinging portion is located downstream of an upstream end of the second roller, When the medium is not being transported, the downstream end of the swinging portion is disposed so as to be located lower than the upstream end thereof, The swinging portion swings in accordance with the thickness of the medium being transported. A medium transport device comprising:

4. 4. The medium transport device according to claim 1, wherein the lower guide is formed of a flexible member.

5. The lower guide further includes a pressing member that presses the lower guide upward.

4. The medium transport device according to claim 1, wherein the lower guide is arranged so as to be movable downward by the pressing member.

6. 5. The medium transport device according to claim 1, wherein the lower guide includes a moving portion that is movable downward, and a support portion that supports the moving portion.

7. A medium transport device as described in any one of claims 1 to 5, configured so that the distance from the position where the lower end of the medium abuts the first roller to the upper end of the first roller is changed by changing the spacing between the pair of guides.

8. A medium transporting device as described in any one of claims 1 to 7, wherein when the medium being transported has a thickness greater than the spacing between the pair of guides at the position where the lower guide and the upper guide are closest to each other when the medium is not being transported, the spacing between the pair of guides can be changed depending on the medium by causing the upper guide to move upward by the leading edge of the medium as the medium passes between the pair of guides, so that the position where the leading edge of the medium abuts on the second roller changes depending on the thickness of the medium.

9. A media transport device as described in any one of claims 1 to 8, wherein the second roller is arranged to be movable upward so as to transport a media having a thickness greater than the distance between the pair of guides at the position where the lower guide and the upper guide are closest to each other when no media is being transported.

10. A media conveying device as described in any one of claims 1 to 9, wherein in the height direction, the distance between the lower end of the second roller and the upper guide located at the uppermost position is greater than or equal to the maximum thickness of the media supported by the media conveying device and less than or equal to 3 / 2 of the maximum thickness.

11. A medium transport device described in any one of claims 1 to 10, wherein in the height direction, the distance between the lower end of the second roller and the upper guide located at the uppermost position is less than 2 / 3 of the roller diameter of the second roller.

12. 12. The medium transport device according to claim 1, wherein a downstream end of the lower guide is located downstream of an upstream end of the first roller in a medium transport direction.

13. A medium transport device as described in any one of claims 1 to 12, configured so that the distance from the position where the lower end of the medium abuts the first roller to the upper end of the first roller is changed by changing the spacing between the upper guide and the lower guide.

14. A media transport device as described in any one of claims 1 to 13, wherein when no media is being transported, the distance between the downstream end of the upper guide in the media transport direction and the downstream end of the lower guide in the media transport direction is smaller than the maximum thickness of media supported by the media transport device.

15. A media transport device as described in any one of claims 1 to 14, wherein the lower guide is arranged so that the first roller protrudes by more than 1 / 3 of the maximum thickness of the media supported by the media transport device, and the upper guide is arranged so that the second roller protrudes by more than 2 / 3 of the maximum thickness of the media supported by the media transport device.

Images