Media transport device, recording device

Abstract

To provide a medium transport device and a recording device that can reduce a load on a conveyed medium with a simple structure while maintaining separation performance of the medium.SOLUTION: The medium transport device includes: a medium placing part 22; a feeding roller 33 for sending a first medium 17f to a transportation direction Dc; a separation roller 34 for separating the first medium 17f from a second medium 17s; a transport roller pair 24 for transporting the first medium 17f sent from the feeding roller 33; and a driving mechanism for driving the separation roller 34, wherein the driving mechanism rotates the separation roller 34 in a second rotation direction R2, and imparts a rotational load of a first load value to the rotation of the separation roller 34 in the first rotational direction R1, after a leading edge of the first medium 17f passes through the transport roller pair 24 and by the time before a trailing edge of the first medium 17f passes between the feeding roller 33 and the separation roller 34, the rotational load imparted to the separation roller 34 is switched from the first load value to a second load value which is smaller than the first load value.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a medium conveyance device and a recording device.

Background Art

[0002] For example, as in Patent Document 1, there is an inkjet printer which is an example of a recording device that performs recording on paper which is an example of a medium. The inkjet printer includes a paper feeding device which is an example of a medium conveyance device. The paper feeding device includes a pickup roller, a feed roller which is an example of a feeding roller, a retard roller which is an example of a separating roller, and a pair of conveyance rollers.

[0003] The feeding device separates the paper sent out by the pickup roller one by one by the feed roller and the retard roller, and then conveys it by the pair of conveyance rollers. The feeding device reduces the conveyance load by separating the feed roller from the paper conveyed by the pair of conveyance rollers, and suppresses double feeding by holding down the next paper with the pickup roller.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] The feeding device of Patent Document 1 moves the feed roller by driving a solenoid. Therefore, the structure becomes complicated.

Means for Solving the Problems

[0006] A media transport device that solves the above problems comprises a media placement section on which a first medium and a second medium are placed, a feed roller for transporting the first medium in the transport direction, a separation roller for nipping the first medium between itself and the feed roller and separating the first medium and the second medium, a pair of transport rollers for transporting the first medium transported from the feed roller, and a drive mechanism for driving the separation roller, wherein the separation roller is rotatable in a first rotation direction which is the direction in which the first medium is transported and in a second rotation direction opposite to the first rotation direction, the drive mechanism rotates the separation roller in the second rotation direction and applies a rotational load of a first load value to the rotation of the separation roller in the first rotation direction, and switches the rotational load applied to the separation roller from a first load value to a second load value smaller than the first load value between the leading edge of the first medium passing the pair of transport rollers and before the trailing edge of the first medium passing between the feed roller and the separation roller.

[0007] A recording device that solves the above problems comprises a medium transport device having the above configuration and a recording unit that performs recording on the first medium. [Brief explanation of the drawing]

[0008] [Figure 1] This is a schematic diagram of one embodiment of a recording device. [Figure 2] This is a schematic diagram of the drive mechanism of the recording device. [Figure 3] This is a schematic diagram showing the feeding mechanism and the pair of conveying rollers. [Figure 4] This is a schematic diagram showing the feeding mechanism and the pair of conveying rollers. [Figure 5] This is a schematic diagram showing the feeding mechanism and the pair of conveying rollers. [Figure 6] This is a schematic diagram showing the feeding mechanism and the pair of conveying rollers. [Modes for carrying out the invention]

[0009] [Embodiment] Hereinafter, an embodiment of the media transport device and recording device will be described with reference to the drawings. The recording device of this embodiment is an inkjet printer that prints by spraying ink, which is an example of a liquid, onto a medium such as paper. In the drawings, the direction of gravity is indicated by the Z axis, assuming that the recording device 11 is placed on a horizontal plane, and the directions along the horizontal plane are indicated by the X and Y axes. The X, Y, and Z axes are orthogonal to each other.

[0010] <Recording device> As shown in Figure 1, the recording device 11 may include a housing 12, a stacker 13, a recording unit 14, a control unit 15, and a media transport device 16.

[0011] The housing 12 houses the various components of the recording device 11. Specifically, the housing 12 houses the recording unit 14, the control unit 15, and the media transport device 16. The stacker 13 receives the media 17 transported by the media transport device 16. The stacker 13 can hold multiple recorded media 17. In this embodiment, two media 17 that are transported consecutively among the multiple media 17 are also referred to as the first media 17f and the second media 17s. The first media 17f is the media 17 that is transported first. The second media 17s is the media 17 that is transported after the first media 17f. In the following description, when the first media 17f and the second media 17s are not distinguished, they are simply referred to as media 17.

[0012] The recording unit 14 may have a nozzle surface 19. Multiple nozzles 20 open on the nozzle surface 19. The recording unit 14 may be positioned so that the nozzle surface 19 is inclined with respect to the horizontal plane. The recording unit 14 records onto the conveyed medium 17 by spraying liquid from the nozzles 20. That is, the recording unit 14 may record onto the first medium 17f. After recording onto the first medium 17f, the recording unit 14 may record onto the second medium 17s. The recording unit 14 in this embodiment is a line head that records onto the conveyed medium 17 while it is stationary.

[0013] The control unit 15 comprehensively controls the driving of each mechanism in the recording device 11 and controls the various operations performed by the recording device 11. The control unit 15 may be configured as a circuit including α: one or more processors that perform various processes according to a computer program, β: one or more dedicated hardware circuits that perform at least some of the various processes, or γ: a combination thereof. The hardware circuit is, for example, an application-specific integrated circuit. The processor includes a CPU and memory such as RAM and ROM, and the memory stores program code or instructions configured to cause the CPU to perform the processes. Memory, or computer-readable media, includes any readable media that can be accessed by a general-purpose or dedicated computer.

[0014] <Media transport device> The media conveying device 16 comprises a media placement section 22, a feeding mechanism 23, and a pair of conveying rollers 24. The media conveying device 16 may also comprise a plurality of media placement sections 22 and the same number of feeding mechanisms 23 as the media placement sections 22. The media conveying device 16 may also comprise a pair of feed rollers 26, a conveying belt 27, a pair of pulleys 28, and a pair of discharge rollers 29.

[0015] The feeding mechanism 23 feeds the media 17 contained in the media mounting section 22 from the corresponding media mounting section 22. Feeding means sending the media 17 one by one from the media mounting section 22 to the transport path 36. The feeding mechanism 23 may also include a moving mechanism 31, a pickup roller 32, a feeding roller 33, and a separation roller 34.

[0016] The transport roller pair 24, the feed roller pair 26, and the discharge roller pair 29 each include a roller that contacts the surface of the medium 17 and a roller that contacts the back surface of the medium 17. Two of the rollers may be a drive roller, one of which is rotationally driven, and a driven roller, the other of which is rotationally driven.

[0017] In FIG. 1, a conveyance path 36 and a reversal path 37 along which a medium 17 is conveyed are indicated by a dashed line. The conveyance path 36 connects the medium placement unit 22 and the stacker 13. The reversal path 37 connects the conveyance path 36 downstream of the recording unit 14 and the conveyance path 36 upstream of the recording unit 14. The reversal path 37 is a path for returning the medium 17 recorded on one side to upstream of the recording unit 14 when recording on both sides of the medium 17. The medium conveyance device 16 may include a flap 38 for switching the path along which the medium 17 is conveyed.

[0018] The medium placement unit 22 may be capable of accommodating a plurality of media 17 in a stacked state. The first medium 17f and the second medium 17s are placed on the medium placement unit 22. "Placed" means being in a state of being placed on top and being movable by applying an external force. When placed on the medium placement unit 22, the first medium 17f is located above the second medium 17s.

[0019] The conveyance roller pair 24 conveys the first medium 17f sent from the feed roller 33. The conveyance roller pair 24 conveys the medium 17 by rotating with the medium 17 sandwiched therebetween. Of the two rollers constituting the conveyance roller pair 24, one roller may be a toothed roller. If the roller that contacts the recorded surface of the medium 17 recorded on one side is a toothed roller, a decrease in recording quality can be suppressed.

[0020] The medium conveyance device 16 may include a plurality of feed roller pairs 26. The plurality of feed roller pairs 26 may be provided on the conveyance path 36 and the reversal path 37. The feed roller pair 26 conveys the medium 17 along the conveyance path 36 or the reversal path 37 by rotating with the medium 17 sandwiched therebetween.

[0021] The conveyor belt 27 may convey the first medium 17f sent from the conveyor roller pair 24. The conveyor belt 27 is an annular belt. The conveyor belt 27 is stretched over a pair of pulleys 28. The conveyor belt 27 circulates around the pair of pulleys 28 as one of the pulleys 28 rotates. The conveyor belt 27 has a conveying surface 40 for conveying the medium 17. The conveying surface 40 is a plane on the outer circumferential surface of the conveyor belt 27 that supports the medium 17, for example, by electrostatic attraction. The conveyor belt 27 may be provided such that the conveying surface 40 is parallel to the nozzle surface 19. The conveyor belt 27 supports the portion of the medium 17 that is recorded by the recording unit 14. The conveyor belt 27 conveys the medium 17 in the conveying direction Dc by circulating while supporting the medium 17. The conveying direction Dc is the direction along the conveying path 36, and is the direction from the medium placement unit 22 toward the stacker 13.

[0022] The discharge roller pair 29 may be provided at the downstream end of the transport path 36. The discharge roller pair 29 rotates with the medium 17 in between, thereby discharging the recorded medium 17 to the stacker 13.

[0023] The moving mechanism 31 moves the pickup roller 32. The moving mechanism 31 may include, for example, a solenoid, a cam, and an air cylinder. The pickup roller 32 in this embodiment is displaceable between a contact position shown in Figure 3 and a separation position shown in Figure 6. The contact position is the position in which it contacts the first medium 17f. The separation position is the position away from the first medium 17f. By rotating at the contact position, the pickup roller 32 feeds the first medium 17f, which is placed on the medium placement section 22, to the feeding roller 33. After feeding out the first medium 17f, the pickup roller 32 feeds out the second medium 17s.

[0024] The feed roller 33 contacts the upper surface of the medium 17 that has been fed by the pickup roller 32. That is, when multiple mediums 17 are fed at once by the pickup roller 32, the feed roller 33 contacts the uppermost first medium 17f. The feed roller 33 feeds the first medium 17f in the transport direction Dc.

[0025] The separation roller 34 nips the first medium 17f between itself and the feeding roller 33. The separation roller 34 is rotatable around the rotation axis 42 in a first rotation direction R1 and a second rotation direction R2. The first rotation direction R1 is the direction in which the first medium 17f is fed in the conveying direction Dc. The second rotation direction R2 is the opposite direction to the first rotation direction R1. The separation roller 34 is not fixed to the rotation axis 42. Therefore, the separation roller 34 is rotatable so as to slide relative to the rotation axis 42.

[0026] As shown in Figure 2, the media transport device 16 may include a drive mechanism 44. The drive mechanism 44 may include a first drive source 45, which is an example of a drive source, a transmission unit 46, and a second drive source 47. The drive mechanism 44 may also include a first torque limiter 48, a second torque limiter 49, and a one-way clutch 50.

[0027] The first drive source 45 may also drive the separation roller 34. The first drive source 45 rotates the rotating shaft 42 in the second rotation direction R2, thereby rotating the separation roller 34 in the second rotation direction R2. In other words, the rotating shaft 42 in this embodiment constitutes a transmission path that transmits the power of the first drive source 45 to the separation roller 34.

[0028] The transmission unit 46 transmits the driving force of the first drive source 45 to the feed roller 33. The transmission unit 46 may also transmit the driving force of the first drive source 45 to the pickup roller 32 shown in Figure 1. That is, the first drive source 45 may rotate the rotating shaft 42, the feed roller 33, and the pickup roller 32.

[0029] The second drive source 47 may drive the drive roller among the transport roller pair 24. The first torque limiter 48 and the second torque limiter 49 may be provided on the rotating shaft 42. The first torque limiter 48 and the second torque limiter 49 may be provided in the transmission path that transmits power from the first drive source 45 to the separation roller 34. The first torque limiter 48 and the second torque limiter 49 may be provided in series in the transmission path. That is, the first torque limiter 48 and the second torque limiter 49 may apply a rotational load to the rotating shaft 42 that constitutes the transmission path.

[0030] The first torque limiter 48 may be fixed to the rotating shaft 42. The first torque limiter 48 may rotate integrally with the rotating shaft 42. The first torque limiter 48 may apply a rotational load of a first load value to the separation roller 34. That is, when the separation roller 34 rotates differently from the rotating shaft 42, a rotational load of a first load value is generated between the first torque limiter 48 and the separation roller 34. When the separation roller 34 rotates at the same rate as the rotating shaft 42, the first torque limiter 48 does not apply a rotational load to the separation roller 34. The first load value may be, for example, 400 gfcm.

[0031] The second torque limiter 49 is fixed, for example, to a frame supporting the rotating shaft 42. The second torque limiter 49 may apply a rotational load of a second load value to the separation roller 34. In this embodiment, the second torque limiter 49 applies a rotational load to the separation roller 34 via the one-way clutch 50 and the rotating shaft 42. The second load value is smaller than the first load value. The second load value may be, for example, 200 gfcm.

[0032] The one-way clutch 50 switches the connection state between the rotating shaft 42 and the second torque limiter 49. The one-way clutch 50 connects the rotating shaft 42, which rotates in the first rotation direction R1, to the second torque limiter 49. The one-way clutch 50 disconnects the rotating shaft 42, which rotates in the second rotation direction R2, from the second torque limiter 49.

[0033] When the rotating shaft 42 rotates in the first rotational direction R1, the one-way clutch 50 rotates together with the rotating shaft 42. As a result, a rotational load of the second load value is generated between the one-way clutch 50 and the second torque limiter 49.

[0034] When the rotating shaft 42 rotates in the second rotational direction R2, the one-way clutch 50 allows the rotating shaft 42 to spin freely. In other words, the second torque limiter 49 does not apply a rotational load to the rotating shaft 42 rotating in the second rotational direction R2.

[0035] <Operation of the Embodiment> The operation of this embodiment will now be described. In Figures 3 to 6, the directions of rotation driven by the first drive source 45 and the second drive source 47 are shown by solid arrows, and the directions of driven rotation relative to the medium 17 and the other rollers are shown by dashed arrows.

[0036] As shown in Figure 3, when supplying the medium 17, the control unit 15 drives the first drive source 45. The first drive source 45 rotates the pickup roller 32, the supply roller 33, and the rotating shaft 42. When the pickup roller 32, which is located at the contact position, rotates, the first medium 17f is supplied.

[0037] The rotating shaft 42 rotates in the second rotational direction R2. Before the first medium 17f reaches the feeding roller 33, the separating roller 34 rotates in the first rotational direction R1, following the feeding roller 33. Since the separating roller 34 rotates in a different direction from the rotating shaft 42 which rotates in the second rotational direction R2, a rotational load is applied to the separating roller 34 by the first torque limiter 48. The one-way clutch 50 disengages the second torque limiter 49 from the separating roller 34 when the first drive source 45 is driven. Therefore, the drive mechanism 44 applies a rotational load of the first load value to the rotation of the separating roller 34 in the first rotational direction R1.

[0038] As shown in Figure 4, when the first medium 17f is fed to the feed roller 33, the feed roller 33 and the separation roller 34 sandwich the first medium 17f. The separation roller 34 moves in accordance with the first medium 17f being fed in the conveying direction Dc, but the rotation direction of the separation roller 34 remains unchanged as the first rotation direction R1. Therefore, the separation roller 34 is subjected to a rotational load of a first load value by the first torque limiter 48.

[0039] As shown in Figure 5, the feeding of the second medium 17s together with the first medium 17f is called double feeding. When the double-fed second medium 17s is fed to the separation roller 34, the separation roller 34 rotates in the second rotation direction R2 due to the load received from the first torque limiter 48, pushing the second medium 17s back. The separation roller 34 separates the first medium 17f and the second medium 17s.

[0040] The control unit 15 may drive the second drive source 47 after the leading edge of the first medium 17f has been transported to the transport roller pair 24. Alternatively, the control unit 15 may drive the second drive source 47 after waiting for the skew of the first medium 17f, which is being abutted against, to be corrected. In other words, the transport roller pair 24 may be so-called resist rollers that correct the skew of the medium 17.

[0041] As shown in Figure 6, the control unit 15 may move the pickup roller 32 to a separated position while the first medium 17f is being transported by the transport roller pair 24. The control unit 15 may stop the first drive source 45 while the pickup roller 32 is in the separated position.

[0042] When the first drive source 45 stops, the feeding roller 33 and the separating roller 34 are driven by the first medium 17f being fed by the transport roller pair 24. The rotating shaft 42 rotates in a manner driven by the separating roller 34. That is, the separating roller 34 and the rotating shaft 42 rotate in the first rotational direction R1. The one-way clutch 50 connects the second torque limiter 49 to the separating roller 34 when the first drive source 45 is not driven. Therefore, when the first drive source 45 stops, the rotational load applied to the separating roller 34 switches from the first load value to the second load value. The separating roller 34, with a rotational load of the second load value applied, can prevent the second medium 17s from passing through the separating roller 34 even if the second medium 17s is being fed in a double feed.

[0043] The pickup roller 32 may move from the contact position to the separated position before the rotational load applied to the separation roller 34 switches from the first load value to the second load value. That is, the pickup roller 32 may move to the separated position before the rotational load switches, or it may move to the separated position at the same time as the rotational load switches.

[0044] The control unit 15 may stop the first drive source 45 after the leading edge of the first medium 17f has passed the transport roller pair 24, but before the trailing edge of the first medium 17f has passed between the feed roller 33 and the separation roller 34. In this embodiment, when the first drive source 45 stops, the rotational load applied to the separation roller 34 switches from the first load value to the second load value. The drive mechanism 44 may switch the rotational load applied to the separation roller 34 from the first load value to the second load value before the leading edge of the first medium 17f reaches the transport belt 27.

[0045] After the rear end of the first medium 17f has passed the feeding roller 33 and the separation roller 34, the control unit 15 moves the pickup roller 32 to the contact position and drives the first drive source 45 to feed the second medium 17s.

[0046] <Effects of the Embodiment> The effects of this embodiment will now be explained. (1) The drive mechanism 44 that drives the separation roller 34 switches the rotation load of the separation roller 34. Therefore, the load on the transported medium 17 can be reduced with a simple structure while maintaining the separation performance of the medium 17.

[0047] (2) The drive mechanism 44 includes a first torque limiter 48 and a second torque limiter 49. The drive mechanism 44 can easily change the rotational load of the separation roller 34 by switching the torque limiter that applies a rotational load to the separation roller 34.

[0048] (3) The first torque limiter 48 and the second torque limiter 49 are installed in series in the transmission path. Therefore, the structure can be made simpler compared to, for example, the case in which the first torque limiter 48 and the second torque limiter 49 are installed in parallel.

[0049] (4) The first torque limiter 48 and the second torque limiter 49 are provided on the same rotating shaft 42. Therefore, the drive mechanism 44 can be made smaller compared to the case where the first torque limiter 48 and the second torque limiter 49 are provided separately.

[0050] (5) The drive mechanism 44 is equipped with a one-way clutch 50. The one-way clutch 50 switches the connection between the second torque limiter 49 and the separation roller 34 in conjunction with the drive of the first drive source 45. Thus, the configuration of the drive mechanism 44 can be simplified.

[0051] (6) The first medium 17f may tilt when the rotational load applied to the separation roller 34 changes. In this regard, the drive mechanism 44 switches the rotational load applied to the separation roller 34 to the second load value before the leading edge of the first medium 17f reaches the conveyor belt 27. Therefore, the risk of the first medium 17f tilting on the conveyor belt 27 can be reduced.

[0052] (7) When the rotational load applied to the separation roller 34 reaches the second load value, the pickup roller 32 is positioned at a distanced position. Therefore, the load applied by the pickup roller 32 to the first medium 17f can be reduced.

[0053] [Example of changes] This embodiment can be implemented with the following modifications. This embodiment and the following modifications can be combined with each other to the extent that they do not contradict each other technically.

[0054] The first drive source 45 may rotate at least one of the following in addition to the rotating shaft 42: the pickup roller 32, the feeding roller 33, the transport roller pair 24, the feed roller pair 26, the pulley 28, and the discharge roller pair 29.

[0055] The first and second load values ​​may be changed depending on the type of medium 17, for example. For example, if the medium 17 is easily separated even when double-feeded, the first and second load values ​​may be smaller than when it is difficult to separate. For example, if the medium 17 is stiff, the first and second load values ​​may be smaller than when it is not stiff. For example, if the width of the medium 17 is small, the first and second load values ​​may be smaller than when the width of the medium 17 is large.

[0056] When the drive of the first drive source 45 is stopped, the pickup roller 32 may be in the contact position. The drive mechanism 44 may stop driving the first drive source 45 after the first medium 17f has reached the conveyor belt 27 but before it is attracted to the conveyor belt 27, or before the recording unit 14 starts recording on the first medium 17f.

[0057] The connection state between the rotating shaft 42 and the second torque limiter 49 may be switched, for example, by the control unit 15 controlling the clutch. The first torque limiter 48 and the second torque limiter 49 may be provided at least one of them in a position different from the rotation axis 42.

[0058] The first torque limiter 48 and the second torque limiter 49 may be provided in parallel with the transmission path, at least one of them. The drive mechanism 44 may change the rotational load applied to the separation roller 34 by switching the power transmission path from the path through the first torque limiter 48 to the path through the second torque limiter 49, for example, using a clutch.

[0059] The drive mechanism 44 may stop driving the rotating shaft 42 by, for example, disengaging the first drive source 45 from the rotating shaft 42 using a clutch. The drive mechanism 44 may have a braking unit that presses friction material against the rotating shaft 42 or the separation roller 34 to limit rotation. The drive mechanism 44 may also switch the rotational load applied to the separation roller 34 using the braking unit.

[0060] The recording unit 14 may be configured as a serial head that scans the medium 17. The media transport device 16 may be provided on a scanner that has a reading unit for reading an image of the media 17.

[0061] The recording device 11 is not limited to an inkjet printer; it may also be a laser printer, thermal printer, dot matrix printer, digital printing press, etc. The recording device 11 may be a liquid ejection device that performs recording by spraying or ejecting liquids other than ink. The state of the liquid ejected from the liquid ejection device as minute droplets may include granular, teardrop-shaped, or thread-like forms. The liquid referred to here may be any material that can be ejected from the liquid ejection device. For example, the liquid may be any state in which a substance is in the liquid phase, and may include highly or low viscosity liquids, sols, gel water, other inorganic solvents, organic solvents, solutions, liquid resins, liquid metals, and other fluids. The liquid may include not only liquids as a state of matter, but also functional materials consisting of particles of solids such as pigments and metal particles dissolved, dispersed, or mixed in a solvent. Typical examples of liquids include inks and liquid crystals as described in the above embodiments. Here, ink refers to general water-based inks and oil-based inks, as well as various liquid compositions such as gel inks and hot-melt inks. Specific examples of liquid spraying devices include devices that spray liquids containing materials such as electrode materials and colorants in the form of dispersion or solution, used in the manufacture of liquid crystal displays, electroluminescent displays, surface-emitting displays, and color filters. Liquid spraying devices may also be devices that spray bio-organic materials used in biochip manufacturing, devices that spray liquid samples used as precision pipettes, printing devices, microdispensers, etc. Liquid spraying devices may also be devices that spray lubricating oil with pinpoint accuracy onto precision machinery such as watches and cameras, or devices that spray transparent resin liquids such as ultraviolet-curing resins onto substrates to form minute hemispherical lenses, optical lenses, etc., used in optical communication elements. Liquid spraying devices may also be devices that spray etching solutions such as acids or alkalis to etch substrates.

[0062] [Definition] As used herein, the expression "at least one" means "one or more" of the desired options. For example, as used herein, "at least one" means "only one option" or "both of the two options" if there are two options. As another example, as used herein, "at least one" means "only one option" or "a combination of two or more any options" if there are three or more options.

[0063] [Note] The technical concepts and their effects that can be understood from the embodiments and modifications described above are described below.

[0064] (A) The media transport device comprises a media placement section on which a first medium and a second medium are placed, a feed roller for transporting the first medium in the transport direction, a separation roller for nipping the first medium between itself and the feed roller and separating the first medium and the second medium, a pair of transport rollers for transporting the first medium transported from the feed roller, and a drive mechanism for driving the separation roller, wherein the separation roller is rotatable in a first rotation direction which is the direction in which the first medium is transported and in a second rotation direction opposite to the first rotation direction, the drive mechanism rotates the separation roller in the second rotation direction and applies a rotation load of a first load value to the rotation of the separation roller in the first rotation direction, and switches the rotation load applied to the separation roller from a first load value to a second load value smaller than the first load value between the leading edge of the first medium passing the pair of transport rollers and before the trailing edge of the first medium passing between the feed roller and the separation roller.

[0065] In this configuration, the drive mechanism that drives the separation roller switches the rotational load of the separation roller. Therefore, the load on the transported medium can be reduced with a simple structure while maintaining the separation performance of the medium.

[0066] (B) In a media transport device, the drive mechanism includes a drive source for driving the separation roller, and a first torque limiter and a second torque limiter provided in a transmission path for transmitting power from the drive source to the separation roller, wherein the first torque limiter applies a rotational load of the first load value to the separation roller, and the second torque limiter applies a rotational load of the second load value to the separation roller.

[0067] In this configuration, the drive mechanism includes a first torque limiter and a second torque limiter. The drive mechanism can easily change the rotational load on the separation roller by switching the torque limiter that applies the rotational load to the separation roller.

[0068] (C) In a media transport device, the first torque limiter and the second torque limiter may be provided in series in the transmission path. In this configuration, the first torque limiter and the second torque limiter are installed in series in the transmission path. Therefore, the structure can be made simpler compared to, for example, the case where the first torque limiter and the second torque limiter are installed in parallel.

[0069] (D) In ​​a media transport device, the second torque limiter may be provided on the rotating shaft together with the first torque limiter. In this configuration, the first torque limiter and the second torque limiter are mounted on the same rotation axis. Therefore, the drive mechanism can be made smaller compared to the case where the first torque limiter and the second torque limiter are mounted separately.

[0070] (E) In a media transport device, the drive mechanism may include a one-way clutch, which may disconnect the second torque limiter and the separation roller when the drive source is driven, and connect the second torque limiter and the separation roller when the drive source is not driven.

[0071] In this configuration, the drive mechanism includes a one-way clutch. The one-way clutch switches the connection between the second torque limiter and the separation roller as the drive source is driven. Therefore, the configuration of the drive mechanism can be simplified.

[0072] (F) The medium transport device includes a transport belt for transporting the first medium sent from the transport roller pair, and the drive mechanism may switch the rotational load applied to the separation roller from a first load value to a second load value before the leading edge of the first medium reaches the transport belt.

[0073] The first medium may tilt when the rotational load applied to the separation roller changes. In this configuration, the drive mechanism switches the rotational load applied to the separation roller to the second load value before the leading edge of the first medium reaches the conveyor belt. Therefore, the risk of the first medium tilting on the conveyor belt can be reduced.

[0074] (G) The media transport device includes a pickup roller that sends the first medium placed on the media placement section to the feed roller, wherein the pickup roller is displaceable between a contact position in contact with the first medium and a separation position away from the first medium, and the pickup roller may move from the contact position to the separation position before the rotational load applied to the separation roller switches from a first load value to a second load value.

[0075] In this configuration, when the rotational load applied to the separation roller reaches the second load value, the pickup roller is positioned at a separated position. Therefore, the load applied by the pickup roller to the first medium can be reduced.

[0076] (H) The recording device comprises a medium transport device having the above configuration and a recording unit that performs recording on the first medium. This configuration can achieve the same effects as the media transport device described above. [Explanation of symbols]

[0077] 11...Recording device, 12...Housing, 13...Stacker, 14...Recording unit, 15...Control unit, 16...Media transport device, 17...Media, 17f...First media, 17s...Second media, 19...Nozzle surface, 20...Nozzle, 22...Media placement unit, 23...Feeding mechanism, 24...Transport roller pair, 26...Feed roller pair, 27...Transport belt, 28...Pulley, 29...Discharge roller pair, 31...Moving mechanism, 32...Pick Up roller, 33...feeding roller, 34...separation roller, 36...conveying path, 37...reversal path, 38...flap, 40...conveying surface, 42...rotating shaft, 44...drive mechanism, 45...first drive source, 46...transmission section, 47...second drive source, 48...first torque limiter, 49...second torque limiter, 50...one-way clutch, Dc...conveying direction, R1...first rotation direction, R2...second rotation direction.

Claims

1. A media mounting section on which the first and second media are placed, A feed roller that delivers the first medium in the transport direction, A separation roller that nips the first medium between itself and the feeding roller, and separates the first medium from the second medium, A pair of conveying rollers that convey the first medium sent from the aforementioned feeding roller, A drive mechanism for driving the separation roller, Equipped with, The drive mechanism includes a drive source for driving the separation roller, a first torque limiter and a second torque limiter provided in a transmission path for transmitting power from the drive source to the separation roller, and a one-way clutch. The first torque limiter applies a rotational load of a first load value to the separation roller, The second torque limiter applies a rotational load to the separation roller with a second load value smaller than the first load value. The separation roller is rotatable in a first rotational direction which is the direction in which the first medium is sent in the conveying direction, and in a second rotational direction opposite to the first rotational direction. The one-way clutch disconnects the second torque limiter and the separation roller when the drive source is operating, and connects the second torque limiter and the separation roller when the drive source is not operating. The aforementioned drive mechanism is The separating roller is rotated in the second rotational direction, A rotational load of a first load value is applied to the rotation of the separation roller in the first rotational direction. A media conveying device characterized in that, after the leading edge of the first medium has passed the conveying roller pair, and before the rear end of the first medium has passed between the feeding roller and the separating roller, the drive source is stopped and the rotational load applied to the separating roller is switched from a first load value to a second load value.

2. The medium transport device according to claim 1, characterized in that the first torque limiter and the second torque limiter are provided in series in the transmission path.

3. The media transport device according to claim 2, characterized in that the second torque limiter is provided on the rotating shaft together with the first torque limiter.

4. The system includes a conveyor belt for conveying the first medium sent from the pair of conveyor rollers, The media conveying device according to any one of claims 1 to 3, characterized in that the drive mechanism switches the rotational load applied to the separation roller from a first load value to a second load value before the leading edge of the first medium reaches the conveyor belt.

5. The system includes a pickup roller that sends the first medium placed on the medium placement section to the feeding roller, The pickup roller is displaceable between a contact position in contact with the first medium and a separation position away from the first medium. The media transport device according to any one of claims 1 to 3, characterized in that the pickup roller moves from the contact position to the separated position before the rotational load applied to the separation roller switches from the first load value to the second load value.

6. A media transport device according to any one of claims 1 to 3, A recording unit that records on the first medium, A recording device characterized by comprising the following features.

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