JP2025081793A - Medium discharge device - Google Patents

Abstract

To prevent a medium from being caught on a loading table in a medium discharging device.SOLUTION: A media discharge device 30 comprises: a loading platform 31 on which media M is loaded; an end fence 32 (an example of a leading edge regulating section) that contacts a leading edge (leading edge trajectory T12) of the media M discharged onto the loading platform 31; an upper surface detection sensor S2 (an example of a sensor) that detects a falling time (an example of behavior) of the media M above the loading platform 31; and a control section 39a that varies a position of the end fence 32 based on a detection result of the upper surface detection sensor S2.SELECTED DRAWING: Figure 5B

Description

The present invention relates to a media ejection device that has a loading platform on which media is loaded.

Conventionally, a method is known in which a paper receiving tray on which paper is stacked is raised and lowered according to the amount of paper loaded so that the height to which paper discharged from an image forming device falls is constant (see, for example, Patent Document 1).

JP 2013-163570 A

A loading platform such as the paper receiving platform described above has grooves on its upper surface into which the bottom ends of the fences (side fences and end fences) fit when the loading platform is raised to its uppermost position. Since the fences move to accommodate a variety of sizes of media, the grooves on the top surface of the loading platform are provided with one that extends in the width direction of the media and one that extends in the discharge direction so that the bottom ends of the fences fit in even when the fences move. Having grooves on the top surface of the loading platform in this way makes it possible to prevent media such as paper from getting under the fence.

When media is discharged onto the loading platform, the stiffness of the media changes depending on the environment, such as temperature and humidity, and the leading edge of the media may droop, especially with media that is not very stiff. In this case, the leading edge of the media may not come into contact with the end fence and may get caught in the groove of the loading platform, causing the media to lean against the top fence upstream in the discharge direction, resulting in poor loading.

To prevent the leading edge of the media from sagging, for example, the media can be curled so that the center of the media's width is positioned upward, giving it stiffness and allowing it to be discharged with force. However, with media discharged in this way or stiff media, the media may bounce back when it hits the end fence, be returned once to the upstream side in the discharge direction, and then fall while moving again downstream in the discharge direction, causing the media to get caught in the grooves of the loading platform. Therefore, in such cases, the media may lean against the top fence on the upstream side in the discharge direction, resulting in poor loading.

The object of the present invention is to provide a media ejection device that can prevent media from getting caught on the loading platform.

In one aspect, the media ejection device includes a loading platform on which media is loaded, a leading edge regulating unit that contacts the leading edge of the media ejected onto the loading platform, a sensor for detecting the behavior of the media above the loading platform, and a control unit that changes the position of the leading edge regulating unit based on the detection results of the sensor.

This aspect prevents the media from getting caught on the loading platform.

1 is a front view showing an internal configuration of a printing system including a medium ejection device according to an embodiment. 1 is a diagram showing a main control configuration of a printing system including a medium ejection device according to an embodiment. FIG. 2 is a front view showing a loading platform and the like in one embodiment. FIG. 2 is a perspective view showing a loading platform and the like in one embodiment. 11 is a front view (part 1) for explaining an example in which the end fence is moved in a direction opposite to the discharge direction in the embodiment; FIG. FIG. 11 is a front view (part 2) for explaining an example in which the end fence is moved in a direction opposite to the discharge direction in the embodiment; FIG. 11 is a front view (part 3) for explaining an example in which the end fence is moved in a direction opposite to the discharge direction in the embodiment; 11 is a front view (part 1) for explaining an example in which the end fence is moved in the discharge direction in the embodiment; FIG. FIG. 11 is a second front view illustrating an example in which the end fence is moved in the discharge direction in the embodiment; FIG. 11 is a front view (part 3) for explaining an example in which the end fence is moved in the discharge direction in the embodiment;

Below, a medium ejection device according to one embodiment of the present invention will be described with reference to the drawings.

Figure 1 shows the internal configuration of a printing system 1 equipped with a media ejection device 30 according to one embodiment.

Figure 2 shows the main control configuration of the printing system 1.

The printing system 1 shown in Figures 1 and 2 includes a printing device 10, an intermediate conveying device 20, and a medium discharge device 30. Note that the up-down, front-back, and left-right directions shown in Figure 1 and Figures 3 to 6C described later are examples for the sake of convenience of explanation, and for example, the up-down direction is the vertical direction, and the front-back and left-right directions are the horizontal directions. Also, in Figure 1, the straight conveying path R1 of the medium M in the printing device 10 and the discharge path R4 of the medium M in the intermediate conveying device 20 are shown by solid lines. Also, in Figure 1, the circulating conveying path R2 of the medium M in the printing device 10 is shown by a two-dot chain line, and the reverse conveying paths R3 and R5 in the printing device 10 and the intermediate conveying device 20 are shown by dashed lines. As an example, the medium M is a sheet-like medium such as a sheet of paper.

As shown in FIG. 1, the printing device 10 includes a medium supply unit 11, a feed roller 12, multiple transport roller pairs 13, an adsorption transport unit 14, a print head 15, transport path switching units 16 and 17, and a loading platform 18. As shown in FIG. 2, the printing device 10 includes a control unit 19a, a memory unit 19b, and an interface unit 19c. Note that although the printing system 1 includes a single printing device 10, it may also include, for example, multiple printing devices arranged in series on the transport path of the medium M.

The medium M is loaded on the medium supply unit 11. The medium supply unit 11 is disposed integrally with the printing device 10, but may be disposed separately from the printing device 10. The feed roller 12 feeds and transports the uppermost medium M among the multiple sheets of media M loaded on the medium supply unit 11. Multiple pairs of transport rollers 13 are disposed on each of the straight transport path R1, the circulatory transport path R2, and the reverse transport path R3 in the printing device 10, and transport the medium M while nipping it. The suction transport unit 14 is disposed to face the print head 15. The suction transport unit 14 transports the medium M by, for example, a belt while suctioning the medium M. The feed roller 12, the multiple transport roller pairs 13, the suction transport unit 14, and the multiple transport roller pairs 21 of the intermediate transport device 20 described later are examples of a transport unit that transports the medium M.

The print head 15 has, for example, a line head type inkjet head (not shown) for each color used for printing. The printing method of the print head 15 may be a printing method other than the inkjet printing method. In other words, the print head 15 is merely one example of a printing unit that prints on the medium M, and this printing unit is not limited to the print head 15 of the inkjet printing method.

The transport path switching unit 16 is, for example, a flipper, and switches the transport path of the medium M on which printing has been performed by the print head 15 between a straight transport path R1 continuing to the intermediate transport device 20 and a circulating transport path R2 continuing to the loading platform 18 or the inverted transport path R3. The transport path switching unit 17 is, for example, a flipper, and switches the circulating transport path R2 of the medium M between a transport path continuing to the loading platform 18 and a transport path continuing to the inverted transport path R3. The loading platform 18 is loaded with the medium M that is not discharged to the medium discharge device 30. The medium M is reversed on the inverted transport path R3, and is transported again to the print head 15, where printing is performed on the opposite side.

The control unit 19a shown in FIG. 2 has one or more processors (e.g., CPU: Central Processing Unit) that function as an arithmetic processing device that controls the operation of the entire printing device 10. This processor controls the operation of each part of the printing device 10 by reading and executing a specific program, for example, from the storage unit 19b or from a storage medium (non-transient computer-readable recording medium) that is detachable from the printing device 10. In this way, the control unit 19a (or the printing device 10) functions as an example of a computer that executes a program. The control unit 19a may control multiple pairs of conveying rollers 21 of the intermediate conveying device 20 described later. Note that the control unit 19a of the printing device 10 may function as the control unit 39a of the medium discharge device 30 described later. In addition, a control unit (e.g., a print control device) that serves as both the control unit 19a of the printing device 10 and the control unit 39a of the medium discharge device 30 may be arranged outside the printing device 10.

The storage unit 19b has memories such as a ROM (Read Only Memory), which is a read-only semiconductor memory in which a specific control program is pre-recorded, and a RAM (Random Access Memory), which is a semiconductor memory that can be written and read at any time and is used as a working memory area as necessary when the processor executes various control programs.

The interface unit 19c exchanges various information with devices such as the medium ejection device 30 and the user terminal. For example, the interface unit 19c receives a print job from the user terminal (or the print control device).

As shown in FIG. 1, the intermediate conveying device 20 includes multiple conveying roller pairs 21. These multiple conveying roller pairs 21 nip and convey the medium M discharged from the printing device 10.

The medium ejection device 30 includes a loading platform 31, an end fence 32, a top fence 33, side fences 34 and 35, an ejection sensor S1, and an upper surface detection sensor S2. As shown in FIG. 2, the medium ejection device 30 also includes a loading platform lifting unit 36, an end drive unit 37, a side drive unit 38, a control unit 39a, a memory unit 39b, and an interface unit 39c.

Although the medium ejection device 30 is disposed separately from the printing device 10, it may be disposed integrally with the printing device 10. That is, the medium ejection device 30 may be disposed as a part of the printing device 10. In addition, the medium ejection device 30 may not be loaded with the medium M printed in the printing device 10, but may be loaded with the medium M ejected from a processing device that performs processing other than printing on the medium M, or from a conveying device that conveys the medium M. In addition, when the intermediate conveying device 20 is omitted, the medium ejection device 30 may directly eject the medium M from the printing device 10. In addition, in the printing system 1, when the medium M ejected from the printing device 10 is conveyed to one of a plurality of medium ejection devices depending on, for example, the size or type, the medium ejection device 30 according to the present embodiment may be at least one of the plurality of medium ejection devices.

The loading platform 31 is loaded with media M that are sequentially discharged from the printing device 10 and sequentially transported by the intermediate transport device 20. The loading platform 31 is arranged so that it can be raised and lowered by driving the loading platform lifting section 36 described below so that the loading surface of the media M is at a constant height. The loading platform 31 may be a belt conveyor or roller conveyor on which the media M is loaded, i.e., a loading platform having a transport means. The loading platform 31 may also be detachably arranged in the media discharge device 30, and when the media M is removed, it may be lowered onto the cart 100 and placed on the cart 100, and removed from the media discharge device 30 together with the media M. The loading platform 31 may also be arranged so that it cannot be raised and lowered.

4, on the upper surface of the loading platform 31, a plurality of ribs 31a extending in the width direction W of the medium M are arranged side by side in the discharge direction A (to the right) on both sides of the width direction W of the medium M. A central protrusion 31b extending in the discharge direction A is provided in the center of the width direction W of the loading platform 31. Each of the ribs 31a and the central protrusion 31b has a rectangular parallelepiped shape. A groove G is formed between the plurality of ribs 31a, and between the rib 31a and the central protrusion 31b. The lower ends of the side fences 34 and 35 fit into the groove G extending in the width direction W between the plurality of ribs 31a when the loading platform 31 is at the upper limit position. The lower end of the end fence 32 fits into the groove G extending in the discharge direction A between the rib 31a and the central protrusion 31b when the loading platform 31 is at the upper limit position. When the loading platform 31 is at its upper limit position, the lower ends of the end fence 32 and the side fences 34 and 35 move along the groove G according to the size of the medium M.

The upper surface of the rib 31a and the upper surface of the central protrusion 31b form the loading surface for the first medium M to be loaded on the loading platform 31. The rib 31a is the same height as the central protrusion 31b at the end on the central side in the width direction W of the loading platform 31, but the height gradually increases in the width direction W so that the ends on both ends in the width direction W of the loading platform 31 are higher than the central protrusion 31b. Therefore, the loading surface for the first medium M on the loading platform 31 forms a V-shape in which the center in the width direction W is horizontal and both ends in the width direction W are located upward when viewed from the left and right sides.

The end fence 32, top fence 33, and side fences 34, 35 (the side fence 34 on the near side is omitted in FIG. 3) shown in FIG. 3 and FIG. 4 are examples of regulating parts that contact the end (periphery) of the medium M discharged onto the loading platform 31. The distance between the end fence 32 and the top fence 33 in the discharge direction A is set to a distance slightly longer than the length of the medium M in the discharge direction A, and the distance between the side fences 34, 35 in the width direction W is set to a distance slightly longer than the length of the medium M in the width direction W. It can be said that the medium M can contact the end fence 32, top fence 33, and side fences 34, 35 during the process of being loaded onto the loading platform 31. Note that in FIG. 3 and FIGS. 5A to 5C and 6A to 6C described later, the discharge sensor S1 and the upper surface detection sensor S2 shown in FIG. 1 are omitted, and the detection optical axis L1 of the discharge sensor S1 and the detection optical axis L2 of the upper surface detection sensor S2 are illustrated by dashed lines.

Unlike the loading platform 31, the end fence 32, top fence 33, and side fences 34 and 35 are arranged so that they cannot be raised or lowered, and are fixed, for example, suspended from the upper part of the medium discharge device 30. The end fence 32 is an example of a leading edge regulating section that contacts the leading edge of the medium M discharged onto the loading platform 31. The top fence 33 is an example of a trailing edge regulating section that contacts the trailing edge of the medium M discharged onto the loading platform 31. The side fences 34 and 35 are an example of a side regulating section that contacts the ends in the width direction W of the medium M discharged onto the loading platform 31.

The end fence 32 is arranged so that it can move in the discharge direction A according to the size of the medium M (its length in the discharge direction A). The side fences 34, 35 are arranged so that they can move in the discharge direction A according to the width of the medium M (its length in the width direction W). The end fence 32 and the top fence 33 may also function as offset guides that offset the loading position of the medium M forward or backward in the discharge direction A by moving forward or backward in the discharge direction A at a specified timing, for example, for each print job.

The discharge sensor S1 shown in FIG. 1 is, for example, disposed at or near the upstream end of the medium discharge device 30 in the discharge direction A, and detects the passage of the medium M discharged toward the loading platform 31. Although the discharge sensor S1 is not shown in FIGS. 3 and 4, the discharge sensor S1 is, for example, a reflection sensor that irradiates detection light (detection optical axis L1) upward and detects the presence or absence of the medium M depending on whether or not it receives the reflected light reflected by the medium M. Alternatively, the discharge sensor S1 may be a transmission sensor having a light emitting unit and a light receiving unit arranged on either side of the discharge path R4 of the medium M, and detects the presence or absence of the medium M depending on whether or not the light receiving unit receives the detection light irradiated by the light emitting unit. The discharge sensor S1 may be disposed in a device such as the intermediate conveying device 20 upstream of the medium discharge device 30 in the discharge direction A, and the detection result of the discharge sensor S1 may be acquired by the control unit 39a described later.

The top surface detection sensor S2 is, for example, a transmission sensor or a reflection sensor that detects the presence or absence of a medium M based on whether or not the light receiving unit receives detection light (detection optical axis L2) horizontally irradiated by the light emitting unit above the height of the loading surface of the medium M on the loading platform 31. Although the top surface detection sensor S2 is not shown in Figures 3 and 4, the light emitting unit and the light receiving unit of the top surface detection sensor S2 are located downstream of the end fence 32 in the discharge direction A and upstream of the top fence 33 in the discharge direction A. Note that the end fence 32 and the top fence 33 are provided with holes (not shown) for passing the detection light irradiated by the light emitting unit, or are located in a position that does not interfere with the detection light. The control unit 39a described later may determine that a jam has occurred based on the fact that the top surface detection sensor S2 does not detect the medium M.

The time from when the discharge sensor S1 detects the medium M until the top surface detection sensor S2 detects the medium M can be considered to be the fall time until the medium M discharged onto the loading platform 31 falls to the specified height. Therefore, the top surface detection sensor S2 can be said to be a sensor for detecting the fall time. Note that since the fall time varies depending on the flight trajectory of the medium M, etc., it can be said that the behavior of the medium M above the loading platform 31 can be detected by detecting the fall time. This behavior may be, for example, a flight trajectory that can be determined based on the height of the medium M discharged from the intermediate conveying device 20. When a sensor is disposed that detects this flight trajectory based on the height of the medium M in flight, etc., this sensor can also be said to be a sensor for detecting the behavior of the medium M.

The sensor for detecting the fall time is not limited to the top surface detection sensor S2, but may be, for example, a sensor that detects the height of the loading surface of the media M using horizontal detection light (loading surface sensor), a sensor that irradiates detection light in a direction other than horizontal (media passage sensor), a sensor that irradiates detection light upward from the loading platform 31 (media presence sensor), or a sensor (contact detection sensor) that is provided on the end fence 32, loading platform 31, etc. and detects contact with the media M.

The loading platform lifting unit 36, the end drive unit 37, and the side drive unit 38 shown in FIG. 2 are, for example, actuators such as motors.

The loading platform lifting unit 36 raises and lowers the loading platform 31 under the drive control of the control unit 39a. The medium ejection device 30 is provided with a sensor (not shown) that detects the above-mentioned loading surface height of the media M on the loading platform 31. Based on the detection result of this loading surface sensor, the control unit 39a controls the loading platform lifting unit 36 to lower the loading platform 31, for example, by a predetermined number of sheets, thereby maintaining the loading surface of the media M at a constant height.

The end drive unit 37 moves the end fence 32 back and forth in the discharge direction A under the drive control of the control unit 39a. The side drive unit 38 moves the side fences 34, 34 in the width direction W under the drive control of the control unit 39a. The end drive unit 37 may also perform offsetting as described above by moving the top fence 33 back and forth in the discharge direction A together with the end fence 32.

The control unit 39a has one or more processors (e.g., a CPU) that function as an arithmetic processing device that controls the operation of the entire medium discharge device 30. For example, the processor reads and executes a predetermined program from the storage unit 39b or from a storage medium (non-transient computer-readable recording medium) that is detachable from the medium discharge device 30, thereby controlling the operation of each unit, such as the loading platform lifting unit 36, the end drive unit 37, and the side drive unit 38. In this way, the control unit 39a (or the medium discharge device 30) functions as an example of a computer that executes a program. The control unit 39a may control multiple pairs of conveying rollers 21 of the intermediate conveying device 20. As will be described in detail later, the control unit 39a changes the position of the end fence 32 based on the detection result of the upper surface detection sensor S2.

The storage unit 39b has memories such as a ROM, which is a read-only semiconductor memory in which a specific control program is pre-recorded, and a RAM, which is a semiconductor memory that can be written and read at any time and is used as a working memory area as necessary when the processor executes various control programs.

The interface unit 39c exchanges various information with devices such as the printing device 10 and the intermediate conveying device 20.

Here, the operation of the medium ejection device 30 will be described using the example of Figures 5A to 5C in which the end fence 32 is moved in the direction opposite to the ejection direction A, and the example of Figures 6A to 6C in which the end fence 32 is moved in the ejection direction A.

Figures 5A to 5C are front views illustrating an example of moving the end fence 32 in the direction opposite to the discharge direction A.

As shown in FIG. 5A, the leading edge (leading edge trajectory T11 is shown by a thick dashed line) of a particularly weak medium such as media M may sag and pass through the detection optical axis L2 of the top surface detection sensor S2 without contacting the end fence 32. In this case, the above-mentioned fall time from the detection optical axis L1 of the discharge sensor S1 to the detection optical axis L2 of the top surface detection sensor S2 is shorter than the reference time. In this way, when the leading edge of the medium M passes through the detection optical axis L2 of the top surface detection sensor S2 without contacting the end fence 32, the leading edge of the first medium M to be loaded on the loading platform 31 (hereinafter also referred to as the first medium M) may get caught in the groove G between the multiple ribs 31a, and the medium M (rear end) may lean against the top fence 33, resulting in poor loading.

The reference time is determined, for example, according to the size (length in the discharge direction A), type (e.g., thickness, material, etc.) and discharge speed (conveyance speed) of the medium M, and may have a range between a long threshold and a short threshold. The control unit 39a may determine whether there is any medium M that is shorter than the reference time based on the fall times of multiple (e.g., all) media M, or may determine whether the average fall time of multiple media M is shorter than the reference time, or may determine whether the fall time of the first medium M loaded on the loading tray 31 in the previous print job is shorter than the reference time.

When the fall time is shorter than the reference time, the control unit 39a controls the end drive unit 37 to move the end fence 32 from the reference position P0 to the approach position P1 in the direction opposite to the discharge direction A, as shown in FIG. 5B, when the medium M on the loading tray 31 is removed and the first medium M to be loaded onto the loading tray 31 is discharged.

The reference position P0 is a position determined according to the size, type, and transport speed of the medium M. When the end fence 32 is at the reference position P0, as described above, the distance between the end fence 32 and the top fence 33 in the discharge direction A is set to a distance slightly longer than the length of the medium M in the discharge direction A. This is merely an example, but this slightly longer length is 3 mm, and the distance moved from the reference position P0 to the approach position P1 is also 3 mm. Therefore, in this example, the end fence 32 at the approach position P1 is spaced from the top fence 33 by a distance equal to the length of the medium M in the discharge direction A. Note that the approach position P1 may be moved farther away from the reference position P0 as the fall time becomes shorter. The distance between the reference position P0 and the approach position P1 may also be changed according to the size and type of the medium M.

When the end fence 32 moves to the approach position P1, the leading edge of the medium M is more likely to come into contact with the end fence 32, as shown by the leading edge trajectory T12 in FIG. 5B with a thick dashed line. When the leading edge of the medium M discharged onto the loading platform 31 comes into contact with the end fence 32, the leading edge of the medium M falls onto the loading platform 31 with its leading edge curled upward, so that the leading edge of the medium M does not get caught in the groove G, reducing the incidence of loading failures.

The leading edge of the medium M that is caught in the groove G is mainly the first medium M that is loaded on the loading platform 31. Therefore, as shown in FIG. 5C, after the first medium M comes into contact with the end fence 32, it is advisable to return the position of the end fence 32 from the approach position P1 to the reference position P0. The timing for returning the position of the end fence 32 from the approach position P1 to the reference position P0 is not limited to immediately after the first medium M comes into contact with the end fence 32, but may be any timing, such as before the second medium M comes into contact with the end fence 32. Note that even for the second or subsequent medium M, if a medium M larger in size than the previously discharged medium M is discharged, the leading edge of the medium M may get caught in the groove G, so it is advisable to move the position of the end fence 32 to the approach position P1, etc., as with the first medium M.

Figures 6A to 6C are front views illustrating an example of moving the end fence 32 in the discharge direction A.

6A, for media M that is particularly stiff, the leading edge (leading edge trajectory T21 is shown by a thick dashed line) does not droop, and rebounds significantly when it comes into contact with the end fence 32. After the media M comes into contact with the end fence 32, it is returned once to the opposite side of the discharge direction A, and then falls again while moving in the discharge direction A. Therefore, the above-mentioned fall time from the detection optical axis L1 of the discharge sensor S1 to the detection optical axis L2 of the top surface detection sensor S2 is longer than the reference time. In this case, too, the leading edge of the first sheet of media M to be loaded on the loading platform 31 is likely to get caught in the grooves G between the multiple ribs 31a, causing the media M to lean against the top fence 33, resulting in poor loading. The control unit 39a may determine whether any medium M has a fall time longer than a reference time based on the fall times of multiple (e.g., all) media M, or may determine whether the average fall time of multiple media M is longer than a reference time, or may determine whether the fall time of the first medium M loaded on the loading tray 31 in the previous print job is longer than the reference time.

In this way, when the fall time is longer than the reference time, the control unit 39a controls the end drive unit 37 to move the end fence 32 from the reference position P0 to the separated position P2 in the discharge direction A when the medium M on the loading platform 31 is removed and the first medium M to be loaded on the loading platform 31 is discharged, as shown in FIG. 6B. This reduces the rebound of the medium M when it comes into contact with the end fence 32, as shown by the thick dashed line in FIG. 6B, so that the leading edge of the medium M does not get caught in the groove G, and the incidence of loading failures decreases.

As shown in FIG. 6C, after the first medium M comes into contact with the end fence 32, the position of the end fence 32 may be returned from the separation position P2 to the reference position P0. The timing for returning the position of the end fence 32 from the separation position P2 to the reference position P0 is not limited to immediately after the first medium M comes into contact with the end fence 32, but may be any timing, such as before the second medium M comes into contact with the end fence 32. Note that the separation position P2 is, for example, a distance of 3 mm from the reference position P0, but the longer the fall time, the farther it may be from the reference position P0. The distance between the reference position P0 and the separation position P2 may also be changed depending on the size and type of the medium M.

In the above example, as shown in Figures 5A to 5C, if the fall time is shorter than the reference time, the end fence 32 moves from the reference position P0 to the approach position P1, and as shown in Figures 6A to 6C, if the fall time is longer than the reference time, the end fence 32 moves from the reference position P0 to the separation position P2. However, if the behavior of the medium M above the loading platform 31 is to detect the height of the medium M to determine the flight trajectory of the medium M instead of the fall time, it is advisable to move the end fence 32 from the reference position P0 to the approach position P1 or the separation position P2 in accordance with the height (flight trajectory) of the medium M.

As described above, when a sensor that is provided on the end fence 32 and detects contact with the medium M is used to detect the time it takes for the medium to fall before it comes into contact with the end fence 32, the opposite of the above example may be used: if the fall time is short, the end fence 32 may be moved from the reference position P0 to the separated position P2, and if the fall time is long, the end fence 32 may be moved from the reference position P0 to the approaching position P1. In this way, the end fence 32 may be moved regardless of the fall time, or the movement direction of the end fence 32 may be changed depending on the length of the fall time.

The amount of movement of the end fence 32 from the reference position P0 to the approach position P1 or the separation position P2 may be adjusted based on environmental information such as the temperature detected by a temperature sensor and the humidity detected by a humidity sensor. In addition, if a sensor such as a transmission sensor that detects that the medium M is leaning against the top fence 33 is arranged, the amount of movement of the end fence 32 from the reference position P0 to the approach position P1 or the separation position P2 may be increased when the medium M is detected leaning. In addition, the movement of the end fence 32 from the reference position P0 to the approach position P1 or the separation position P2 based on the behavior of the medium M above the loading platform 31 (for example, the fall time) may be switched between being performed and not being performed depending on the user's settings of the medium discharge device 30 (or the printing system 1).

In the above explanation, an example was described in which the leading edge of the medium M gets caught in the groove G and leans against the top fence 33, but even if the loading platform 31 does not have the groove G (rib 31a and central protrusion 31b), the leading edge of the medium M may get caught on a protrusion or the like provided on the upper surface of the loading platform 31, so the way in which the medium M gets caught is not limited to the groove G of the loading platform 31. In the above explanation, the end fence 32 was given as an example of a leading edge regulating part that contacts the leading edge of the medium M, but the position of the leading edge regulating part that moves independently of the end fence 32 may be changed based on the behavior of the medium M (for example, the falling time).

In the present embodiment described above, the medium discharge device 30 includes a loading platform 31 on which the medium M is loaded, an end fence 32 which is an example of a leading edge regulating section that contacts the leading edge of the medium M discharged onto the loading platform 31, a top surface detection sensor S2 which is an example of a sensor for detecting the fall time (an example of behavior) of the medium M above the loading platform 31, and a control unit 39a which changes the position of the end fence 32 based on the detection result of the top surface detection sensor S2.

However, when the condition (such as stiffness) of the medium M changes due to the environment such as the temperature and humidity around the medium discharge device 30, for example, even if the same medium M is discharged at the same discharge speed, the leading edge (see leading edge trajectory T11) may be discharged with the leading edge drooping as shown in Fig. 5A, or the leading edge (see leading edge trajectory T21) may collide with the end fence 32 with force and bounce back significantly as shown in Fig. 6A. Therefore, for medium M that is determined to be discharged with the leading edge drooping based on behavior such as the fall time, the end fence 32 can be moved from the reference position P0 to the approach position P1 in the direction opposite to the discharge direction A as shown in Fig. 5B, making it easier for the leading edge of the medium M (see leading edge trajectory T12) to come into contact with the end fence 32. Furthermore, for media M that is determined to have a large bounce based on behavior such as the time it falls, as shown in FIG. 6B, the end fence 32 can be moved from the reference position P0 to the separated position P2 in the discharge direction A to reduce the bounce of the media M after the leading end (leading end trajectory T22) of the media M comes into contact with the end fence 32. This makes it less likely for the leading end of the media M to get caught in the groove G provided on the top surface of the loading platform 31. Therefore, according to this embodiment, it is possible to prevent the media M from getting caught on the loading platform 31. This makes it possible to prevent loading problems that occur when the media M leans against the top fence 33 upstream in the discharge direction A.

In addition, in this embodiment, the sensor for detecting the behavior of the medium M is a top surface detection sensor S2, which is an example of a sensor for detecting the fall time until the medium M discharged onto the loading platform 31 falls to a specified height, and the control unit 39a changes the position of the end fence 32 based on the fall time.

As a result, the behavior of the leading edge of the ejected medium M drooping or colliding with the end fence 32 with force due to changes in the environment around the medium ejection device 30, such as the temperature and humidity, can be easily predicted using the fall time, compared to the manner in which the behavior is determined by the flight trajectory of the medium M, such as its height. Therefore, it is easy to prevent the medium M from getting caught on the loading platform 31.

In addition, in this embodiment, the control unit 39a moves the position of the end fence 32 in the direction opposite to the discharge direction A of the medium M (approaching position P1) when the fall time is shorter than the reference time, and moves the position of the end fence 32 in the discharge direction A of the medium M (disengaging position P2) when the fall time is longer than the reference time.

This makes it possible to easily and reliably determine, using the fall time, whether the leading edge of the discharged medium M is drooping or whether the leading edge of the medium M is colliding with the end fence 32 with force. Therefore, it is possible to easily and reliably prevent the medium M from getting caught on the loading platform 31.

In addition, in this embodiment, the control unit 39a changes the position of the end fence 32 from the reference position P0 to, for example, the approach position P1 or the separation position P2 before the first medium M to be loaded on the loading platform 31 contacts the end fence 32 based on the detection result of the upper surface detection sensor S2, and returns the position of the end fence 32 to the reference position P0 after the first medium M to be loaded contacts the end fence 32.

As a result, for the second and subsequent media M that are less likely to get caught on the loading platform 31 due to the first media M being loaded on the loading platform 31, the end fence 32 is positioned at the reference position P0 that is suitable for loading the media M in an orderly manner, so that the media M can be loaded in an orderly manner.

The present invention is not limited to the above-described embodiment as it is, and can be embodied by modifying the components without departing from the gist of the invention in the implementation stage. In addition, various inventions can be formed by appropriately combining the multiple components disclosed in the above-described embodiment. For example, all the components shown in the embodiment can be appropriately combined. Of course, various modifications and applications are possible without departing from the spirit of the invention. The invention described in the claims of the original application of this application is described below.

[Appendix 1]
a loading platform on which the media is loaded;
a leading edge regulating portion that contacts the leading edge of the medium discharged onto the stacking table;
a sensor for detecting the movement of the medium above the loading platform;
a control unit that changes a position of the leading edge regulating unit based on a detection result of the sensor.

[Appendix 2]
the sensor is a sensor for detecting a fall time until the medium discharged onto the stacking platform falls to a specified height,
2. The medium ejection device according to claim 1, wherein the control unit varies a position of the leading edge regulating unit based on the fall time.

[Appendix 3]
the control unit moves a position of the leading edge regulating unit in a direction opposite to a direction in which the medium is discharged when the fall time is shorter than a reference time, and moves a position of the leading edge regulating unit in the direction in which the medium is discharged when the fall time is longer than the reference time.
3. The medium ejection device according to claim 2.

[Appendix 4]
The control unit, based on the detection result, changes the position of the leading edge regulating portion from a reference position before the first sheet of media to be loaded on the loading tray contacts the leading edge regulating portion, and returns the position of the leading edge regulating portion to the reference position after the first sheet of media to be loaded contacts the leading edge regulating portion.

LIST OF SYMBOLS 1 Printing system 10 Printing device 11 Media supply section 12 Feed roller 13 Pair of transport rollers 14 Suction transport section 15 Print head 16, 17 Transport path switching section 18 Loading table 19a Control section 19b Memory section 19c Interface section 20 Intermediate transport device 21 Pair of transport rollers 30 Media discharge device 31 Loading table 31a Rib 31b Central protrusion 32 End fence 33 Top fence 34, 35 Side fence 36 Loading table lifting section 37 End drive section 38 Side drive section 39a Control section 39b Memory section 39c Interface section 100 Cart A Discharge direction G Groove L1, L2 Detection optical axis M Media P0 Reference position P1 Approach position P2 Separation position R1 Straight conveying path R2 Circulating conveying path R3 Reverse conveying path R4 Discharge path R5 Reverse conveying path S1 Discharge sensor S2 Top surface detection sensor T Leading edge trajectory W Width direction

Claims (4)

a loading platform on which the media is loaded;
a leading edge regulating portion that contacts the leading edge of the medium discharged onto the stacking table;
a sensor for detecting the movement of the medium above the loading platform;
a control unit that changes a position of the leading edge regulating unit based on a detection result of the sensor. the sensor is a sensor for detecting a fall time until the medium discharged onto the stacking platform falls to a specified height,
The medium ejection device according to claim 1 , wherein the control unit varies a position of the leading edge regulating unit based on the fall time. the control unit moves a position of the leading edge regulating unit in a direction opposite to a direction in which the medium is discharged when the fall time is shorter than a reference time, and moves a position of the leading edge regulating unit in the direction in which the medium is discharged when the fall time is longer than the reference time.
3. The medium ejection device according to claim 2. The medium ejection device according to any one of claims 1 to 3, characterized in that, based on the detection result, the control unit changes the position of the leading edge regulating portion from a reference position before the first sheet of media to be loaded on the loading tray comes into contact with the leading edge regulating portion, and returns the position of the leading edge regulating portion to the reference position after the first sheet of media to be loaded comes into contact with the leading edge regulating portion.