JP7435014B2 - Sheet loading device, printing device - Google Patents

Description

The present invention relates to a sheet stacking device and a printing device.

2. Description of the Related Art Some printing apparatuses include, for example, a paper ejecting device that removes air between sheets by blowing air toward the sheets when stacking and ejecting printed sheets.

For example, in a paper ejection device that is provided in an image forming apparatus and that places sheets on which images have been formed on a paper ejection tray, a first an alignment surface, an air blowing section provided inside the image forming apparatus that generates an airflow from above the paper ejection tray toward the first alignment surface, and an air blower that ejects sheets from above the entrance side of the paper ejection tray toward the first alignment surface. 2. Description of the Related Art A paper ejection device is known that includes a first auxiliary air blower that generates an airflow in a direction that presses it against a tray (Patent Document 1).

Japanese Patent Application Publication No. 2002-167106

By the way, when the sheet is conveyed while guiding the leading end of the sheet with a movable guide member, in the configuration disclosed in Patent Document 1, since air is blown from above the entrance side of the paper ejection tray, the guide A problem arises in that the sheet falls off from the member.

The present invention has been made in view of the above problems, and an object of the present invention is to make it possible to reliably guide a sheet to a predetermined position.

In order to solve the above problems, the sheet stacking device according to the present invention includes:
a stacking section on which a bundle of sheets is stacked;
a guide means for receiving a leading end of a sheet conveyed toward the stacking section and guiding it downstream in the sheet conveyance direction;
and a blowing means for blowing air toward the sheet,
The blowing means blows air toward the sheet above the stacking section and downstream in the sheet conveyance direction from a position where the guide means is separated from the leading end of the sheet ,
An auxiliary blowing means is arranged upstream of the blowing means in the sheet conveyance direction,
The auxiliary blowing means blows air toward the sheet at a position upstream in the sheet conveyance direction from a position where the guide means leaves the leading end of the sheet;
The blowout amount per unit time of the auxiliary blowout means is smaller than the blowout amount per unit time of the blowout means.
The structure is as follows.

According to the present invention, the sheet can be reliably guided to a predetermined position.

1 is a schematic explanatory diagram of a printing apparatus according to a first embodiment of the present invention. FIG. 2 is an explanatory plan view of a discharge unit of the printing apparatus. FIG. 1 is an explanatory diagram of a sheet stacking device according to a first embodiment of the present invention. FIG. 6 is an explanatory diagram illustrating the arrangement position of the blowing means. FIG. 3 is an explanatory diagram for explaining the operation of the embodiment. FIG. 6 is an explanatory diagram also used to explain the operation. FIG. 3 is an explanatory diagram of a sheet stacking device according to a second embodiment of the present invention. FIG. 7 is an explanatory diagram of a sheet stacking device according to a third embodiment of the present invention. FIG. 7 is an explanatory diagram of a sheet stacking device according to a fourth embodiment of the present invention. FIG. 7 is an explanatory diagram of a sheet stacking device according to a fifth embodiment of the present invention. FIG. 7 is an explanatory diagram of a sheet stacking device according to a sixth embodiment of the present invention. FIG. 7 is an explanatory diagram of a sheet stacking device according to a seventh embodiment of the present invention. FIG. 7 is an explanatory diagram of a sheet stacking device according to an eighth embodiment of the present invention.

Embodiments of the present invention will be described below with reference to the accompanying drawings. First, an example of a printing apparatus according to the present invention will be described with reference to FIGS. 1 and 2. FIG. 1 is a schematic explanatory diagram of the printing apparatus, and FIG. 2 is a plan explanatory diagram of an example of a discharge unit of the printing apparatus.

The printing device 1 includes a carry-in section 10, a printing section 20, a drying section 30, and a carry-out section 40, which is a sheet stacking device according to the present invention. The printing apparatus 1 performs necessary printing by applying liquid to the sheet P carried in from the carrying-in section 10 in the printing section 20, and after drying the liquid adhering to the sheet P in the drying section 30, the sheet P is is discharged to the unloading section 40.

The carry-in unit 10 includes a carry-in tray 11 on which a plurality of sheets P are stacked, a feeding device 12 that separates and feeds the sheets P one by one from the carry-in tray 11, and a pair of registration rollers 13 that feeds the sheets P to the printing unit 20. It is equipped with

As the feeding device 12, any feeding device can be used, such as a device using rollers or a device using air suction. After the leading edge of the sheet P sent out from the carry-in tray 11 by the feeding device 12 reaches the pair of registration rollers 13, the pair of registration rollers 13 is driven at a predetermined timing to be sent to the printing unit 20.

The printing section 20 includes a sheet conveying device 21 that conveys the sheet P. The sheet conveying device 21 includes a drum 51 that is a supporting member (rotating member) that rotates while supporting the sheet P on its circumferential surface, a suction device 52 that is a suction means that generates a suction force on the circumferential surface of the drum 51, and the like. ing. Further, the printing section 20 includes a liquid ejecting section 22 that ejects liquid toward the sheet P carried by the drum 51 of the sheet conveying device 21 .

The printing section 20 also includes a transfer cylinder 24 that receives the fed sheet P and transfers the sheet P to and from the drum 51, and a transfer cylinder 25 that transfers the sheet P conveyed by the drum 51 to the drying section 30. ing.

The leading end of the sheet P conveyed from the carry-in section 10 to the printing section 20 is gripped by a gripping means (sheet gripper) provided on the transfer cylinder 24, and is conveyed as the transfer cylinder 24 rotates. The sheet P conveyed by the transfer cylinder 24 is transferred to the drum 51 at a position facing the drum 51.

A gripping means (sheet gripper) is also provided on the surface of the drum 51, and the leading end of the sheet P is gripped by the gripping means (sheet gripper). A plurality of suction holes are formed in a distributed manner on the surface of the drum 51. A suction device 52 serving as suction means generates a suction airflow directed inward from a required suction hole of the drum 51.

The leading end of the sheet P transferred from the transfer drum 24 to the drum 51 is gripped by the sheet gripper 106, and is suctioned and supported on the drum 51 by the suction airflow by the suction device 52, and as the drum 51 rotates. transported.

The liquid discharge section 22 includes a discharge unit 23 (23A to 23F) which is a liquid discharge means. For example, the discharge unit 23A discharges cyan (C) liquid, the discharge unit 23B discharges magenta (M) liquid, the discharge unit 23C discharges yellow (Y) liquid, and the discharge unit 23D discharges black (K) liquid. Discharge each. Further, the discharge units 23F, 23F are used to discharge any of YMCK, or special liquids such as white and gold (silver). Furthermore, a discharge unit for discharging a treatment liquid such as a surface coating liquid can also be provided.

The ejection unit 23 is, for example, a full-line head in which a plurality of liquid ejection heads 125 each having a nozzle row 126 in which a plurality of nozzles are arranged are arranged on a base member 127, as shown in FIG.

The ejection operation of each ejection unit 23 of the liquid ejection section 22 is controlled by a drive signal according to print information. When the sheet P carried by the drum passes through an area facing the liquid ejection section 22, liquids of each color are ejected from the ejection unit 23, and an image corresponding to the print information is printed.

The drying section 30 includes a drying mechanism section 31 for drying the liquid adhering to the sheet P in the printing section 20, and a suction mechanism section 31 for drying the liquid adhering to the sheet P in the printing section 20, and a suction mechanism for conveying the sheet P conveyed from the printing section 20 in a suction state. The transport mechanism section 32 is also provided.

The sheet P conveyed from the printing section 20 is received by the suction conveyance mechanism section 32, then conveyed so as to pass through the drying mechanism section 31, and delivered to the discharge section 40.

When passing through the drying mechanism section 31, the liquid on the sheet P is subjected to a drying process. As a result, liquid components such as water in the liquid evaporate, the colorant contained in the liquid is fixed on the sheet P, and curling of the sheet P is suppressed.

The carry-out section 40 includes a stack section 401 that is a stack section on which the sheet bundle PB is stacked. The sheets P conveyed from the drying section 30 are sequentially stacked and held on the stack section 401.

Note that the printing apparatus 1 may include, for example, a pre-processing section that performs pre-processing on the sheet P disposed upstream of the printing section 20, or a post-processing section that performs post-processing on the sheet P to which liquid has adhered. may also be placed between the drying section 30 and the unloading section 40.

Examples of the pre-treatment section include one that performs a pre-coating process in which a treatment liquid is applied to the sheet P to suppress bleeding by reacting with the liquid. In addition, the post-processing section includes, for example, a sheet reversing conveyance process for inverting the sheet printed in the printing section 20 and sending it again to the printing section 20 to print on both sides of the sheet P, and binding a plurality of sheets. Examples include those that perform processing.

Further, although an example has been described in which a liquid ejection means is provided as the printing section, printing can also be performed by means other than liquid ejection.

Next, a first embodiment of the present invention will be described with reference to FIGS. 3 and 4. FIG. 3 is an explanatory diagram of the sheet stacking device according to the same embodiment, and FIG. 4 is an explanatory diagram for explaining the arrangement position of the blowing means.

The sheet stacking device 400 includes a stacking section 401 that is a stacking section on which a sheet bundle PB is stacked, and conveying rollers 402 that convey the sheets P toward the stacking section 401.

A guide means 403 is provided for receiving the leading end of the sheet P sent out from the conveying rollers 402 and conveyed toward the stacking section 401 and guiding it downstream in the sheet conveying direction.

The stack unit 401 includes a table 411 on which the sheet bundle PB is stacked, a front end fence (jogger) 412, a rear end fence 413, fences on both sides, and the like.

A conveyance roller 404 that conveys the sheet P fed from the drying section 30 is also arranged upstream of the conveyance roller 402 in the sheet conveyance direction.

The guide means 403 includes an endless belt 433 stretched between a driving roller 431 and a driven roller 432, and a guide member 434 attached to the endless belt 433.

In the guiding means 403, when the sheet P is detected upstream of the conveying rollers 402, the endless belt 433 moves around after a certain period of time, and the guide member 434 and the conveying rollers 402 are guided by the difference in linear speed between the guide member 434 and the conveying roller 402. The leading end of the sheet P is inserted into the member 434. The guide member 434 receives the leading end of the sheet P at the position shown in FIG. 3 (guidance start position S) and starts guiding the sheet P. Then, as the endless belt 433 rotates, the guide member 434 moves and guides the sheet P toward the downstream side in the sheet conveyance direction while holding the leading end of the sheet P.

Here, the guide member 434 has a gap larger than the thickness of the sheet P, and only the leading end of the sheet P is inserted into the guide member 434, and does not have a gripping force to grip the sheet P. The guide member 434 has a role of guiding the leading end of the sheet P, and has a function of suppressing flapping from the leading end of the sheet P to the middle abdomen.

When the guide member 434 reaches the guide end position E in FIG. 4, the linear speed of the guide member 434 is made higher than the linear speed of the conveying rollers 402. As a result, the leading end of the sheet P separates from the guide member 434.

Further, a blowing means 405 for blowing air toward the sheet P is provided. The blowing means 405 is directed toward the sheet P above the stack section 401 which is a stacking section and on the downstream side in the sheet conveyance direction from the position where the guide member 434 of the guide means 403 receives the leading end of the sheet P. Blow out the air.

Here, the blowing unit 405 blows air toward the sheet P on the downstream side in the sheet conveyance direction from the position where the guide member 434 of the guiding unit 403 leaves the leading end of the sheet P (guidance end position).

Note that instead of the guide member 434, a clip having a gripping force to grip the sheet P may be used.

Further, in this embodiment, the blowing means 405 is constituted by two blowing fans 451, 451 forming two blowing sections arranged in the sheet conveyance direction.

Next, the operation of this embodiment will be explained with reference also to FIGS. 5 and 6. 5 and 6 are explanatory diagrams for explaining the same.

The leading end of the sheet P conveyed by the conveyance rollers 402 is held by a guide member 434 of the guide means 403, and is guided by the guide member 434 to the end position of guidance by the guide means 403, as shown in FIG. As described above, the blowing means 405 is disposed downstream of the guide member 434's guide end position in the sheet conveyance direction, in this embodiment, downstream of half the length of the stack section 401 in the sheet conveyance direction. ing.

On the other hand, the blowing means 405 blows out air 500 toward the stack section 401 from above. An airflow 501 caused by the blown air 500 hits the stack portion 401 and then escapes in the front, rear, left and right directions. As a result, the air accumulated between the sheets P is pushed out and removed from between the sheets P.

At this time, the airflow 501a heading upstream in the sheet conveyance direction passes below the sheet P being conveyed and exits to the rear end fence 413 side, so no force is applied to the sheet P in the direction of falling off the guide member 434. .

Thereby, the sheet P can be guided to a predetermined position by the guide member 434 of the guide means 403.

After the guide member 434 of the guide means 403 reaches the guide end position, the moving speed of the guide member 434 is accelerated as shown in FIG. , the tip portion separates from the guide member 434.

The sheet P whose leading end has separated from the guide member 434 is moved in the sheet conveying direction by the conveying force of the conveying rollers 402 and is blown with air 500 from above by the blowing means 405 .

As a result, the air between the sheets P and the stacked sheet bundle PB is removed, and the sheets P fall onto the upper surface of the sheet bundle PB, completing the stacking of the sheets P.

At this time, the blowing out of the air 500 by the blowing means 405 starts after the guide member 434 starts accelerating, that is, when the guide member 434 of the guiding means 403 leaves the leading end of the sheet P.

Thereby, while guiding by the guide member 434, the sheet P can be reliably pressed from above and the air between the sheets P can be removed.

In addition, the heavier the sheet P is, the less it is affected by the airflow 501 caused by the air 500 blown out from the blowing means 405. Adjustment is preferred.

Next, a second embodiment of the present invention will be described with reference to FIG. 7. FIG. 7 is an explanatory diagram of the sheet stacking device according to the same embodiment.

In this embodiment, an auxiliary blowout means 406 is arranged upstream of the blowout means 405 in the sheet conveyance direction. The auxiliary blowing unit 406 blows air toward the sheet P on the upstream side in the sheet conveyance direction from the position where the guide member 434 of the guiding unit 403 leaves the leading end of the sheet P.

The auxiliary blowing means 406 is composed of two blowing fans 461, 461, and blows out air 500 at a weak blowing amount (air volume) such that the sheet P held by the guide member 434 does not fall off from the guide member 434.

Therefore, the amount of blowing per unit time of the auxiliary blowing means 406 is smaller than the amount of blowing per unit time of the blowing means 405.

Next, a third embodiment of the present invention will be described with reference to FIG. FIG. 8 is an explanatory diagram of the sheet stacking device according to the same embodiment.

In this embodiment, the blowing means 405 is arranged to blow out the air 500 diagonally downward on the upstream side in the sheet conveyance direction.

Thereby, it is possible to prevent the guide member 434 of the guide means 403 of the sheet P from falling off from the guide member 434, and to secure a large area for venting air between the sheets P.

Next, a fourth embodiment of the present invention will be described with reference to FIG. 9. FIG. 9 is an explanatory diagram of the sheet stacking device according to the same embodiment.

In this embodiment, the blowing means 405 is composed of a plurality of blowing fans 451A and 451B arranged in a direction intersecting the sheet conveyance direction. In the direction intersecting the sheet conveyance direction, the blowing amount per unit time of the blower fan 451A that blows out 500A of air toward the center of the sheet P is as follows. The amount of balloons is larger than the amount of balloons per unit time.

As a result, the center of the sheet P lands first, and as shown by airflow 503, the air in the center between the sheets P tends to move toward the ends, leaving the air between the sheets P in the center. It can be removed without fail.

Next, a fifth embodiment of the present invention will be described with reference to FIG. 10. FIG. 10 is an explanatory diagram of the sheet stacking device according to the same embodiment.

In this embodiment, a suction fan 407, which is a suction means for sucking air between the sheets P from the side of the stack section 401, is disposed. The suction fan 407 is disposed on the upstream side of the stack section 401 in the sheet conveyance direction, here, on the outside of the upstream fence 413.

This makes it possible to reliably evacuate air on the upstream side, which is difficult to evacuate using only the blowing means 405 disposed on the downstream side.

Next, a sixth embodiment of the present invention will be described with reference to FIG. 11. FIG. 11 is an explanatory diagram of the sheet stacking device according to the same embodiment.

In this embodiment, the outlet side of a duct 408 connected to the exhaust side of the suction fan 407 of the fifth embodiment is arranged as a blowing means 405 to blow out the air exhausted from the suction fan 407. In other words, the blowing means 405 itself does not need to include a blowing means, and may simply be an air blowing port.

This simplifies configuration.

Next, a seventh embodiment of the present invention will be described with reference to FIG. 12. FIG. 12 is an explanatory diagram of the sheet stacking device according to the same embodiment.

In this embodiment, a filter 409 is arranged in a duct 408 which is a path connecting the suction fan 407 and the blowing means 405 in the sixth embodiment.

This makes it possible to collect foreign matter such as paper powder and dirt inside the device and reduce the accumulation of foreign matter on mechanical parts such as gears and chains.

Next, an eighth embodiment of the present invention will be described with reference to FIG. 13. FIG. 13 is an explanatory diagram of the sheet stacking device according to the same embodiment.

In this embodiment, the second blowing means 419 is arranged upstream of the blowing means 405 in the sheet conveyance direction. The second blowing means 419 is located upstream in the sheet conveying direction of the position where the guide member 434 of the guide means 403 leaves the leading end of the sheet P (guidance end position), and the guide member 434 of the guide means 403 Air is blown toward the sheet P on the downstream side of the position at which guidance of the leading end of the sheet P starts (guidance start position).

This second blowing means 419 is composed of two blowing fans 491, 491, and has a blowing amount (air volume) such that the sheet P held by the guide member 434 does not fall off from the guide member 434. Air 500 is blown out at the same amount as the blowing fans 451 and 451.

Therefore, the amount of blowing per unit time of the second blowing means 419 is the same as the amount of blowing per unit time of the blowing means 405.

Note that the blowout amount per unit time of the two blowing fans 491 and 491 of the second blowing means 419 is within a range in which the sheet P held by the guide member 434 does not fall off from the guide member 434. may be larger than the amount of blowing per unit time.

In each of the first to eighth embodiments described above, the blowing means 405, the auxiliary blowing means 406, and the second blowing means 419 are located at the positions where the guide member 434 of the guiding means 403 receives the leading end of the sheet P. Air is blown toward the sheet P on the downstream side in the sheet conveyance direction from the (guidance start position).

This prevents the leading end of the sheet P from flapping due to the influence of air blowing between the position where the sheet P is held by the conveying rollers 402 and the guiding start position of the guiding means 403. Therefore, the leading end of the sheet P conveyed from the conveying rollers 402 can be reliably inserted into the guide member 434 of the guide means 403, and the guide means 403 can reliably guide the sheet P.

Note that in each of the above embodiments, the printing unit 20 of the printing apparatus 1 has a configuration that performs required printing on the sheet P using toner instead of applying liquid such as ink to perform required printing on the sheet P. You can also use it as

Furthermore, the material of the sheet P to be conveyed is not limited to paper, and the present invention may be applied to devices that convey plastic films, cloth, metal sheets, and the like.

1 Printing device 10 Carrying-in section 20 Printing section 21 Sheet conveying device 22 Liquid discharging section 23 Discharging unit 40 Carrying-out section 400 Sheet stacking device 401 Stack section (loading section)
401 Conveying roller 403 Guide means 405 Blowing means 407 Suction fan (suction means)
434 Guide member 419 Second blowing means

Claims (13)

a stacking section on which a bundle of sheets is stacked;
a guide means for receiving a leading end of a sheet conveyed toward the stacking section and guiding it downstream in the sheet conveyance direction;
and a blowing means for blowing air toward the sheet,
The blowing means blows air toward the sheet above the stacking section and downstream in the sheet conveyance direction from a position where the guide means is separated from the leading end of the sheet ,
An auxiliary blowing means is arranged upstream of the blowing means in the sheet conveyance direction,
The auxiliary blowing means blows air toward the sheet at a position upstream in the sheet conveyance direction from a position where the guide means leaves the leading end of the sheet;
The blowing amount per unit time of the auxiliary blowing means is smaller than the blowing amount per unit time of the blowing means.
A sheet loading device characterized by: The blowing means is
The sheet stacking device according to claim 1, further comprising a plurality of balloons arranged in the sheet conveyance direction. 3. The sheet stacking device according to claim 1, wherein the blowing means starts blowing out the air when the guide means leaves the leading end of the sheet. A second blowing means is arranged upstream of the blowing means in the sheet conveyance direction,
The second blowing means is located upstream in the sheet conveying direction from a position where the guiding means leaves the leading edge of the sheet, and further upstream in the sheet conveying direction from a position where the guiding means receives the leading edge of the sheet. The sheet stacking device according to claim 1 , wherein air is blown toward the sheet on the downstream side. 5. The sheet stacking device according to claim 4 , wherein the blowout amount per unit time of the second blowout means is the same as or larger than the blowout amount per unit time of the blowout means. 6. The sheet stacking device according to claim 1, wherein the amount of air blown from the air blowing means per unit time is changed according to the weight of the sheet. 7. The sheet stacking device according to claim 1, wherein the blowing means blows air toward an upstream side in the sheet conveyance direction and diagonally downward. The blowing means has a plurality of blowing portions arranged in a direction intersecting the sheet conveyance direction,
In the direction intersecting the sheet conveyance direction, the blowout amount per unit time of the blowout section that blows air toward the center of the sheet is equal to the blowout amount per unit time of the blowout section that blows air toward the edge of the sheet. The sheet stacking device according to any one of claims 1 to 6 , characterized in that the sheet stacking device is larger than the amount. 9. The sheet stacking apparatus according to claim 1, further comprising a suction means for sucking air between the sheets on a side of the stacking section. 10. The sheet stacking device according to claim 9 , wherein the suction means is disposed upstream of the stacking section in the sheet conveyance direction. The blowing means is
connected to the exhaust side of the suction means,
The sheet stacking device according to claim 9 or 10, characterized in that the air to be exhausted is blown out from the suction means. 12. The sheet stacking device according to claim 11 , further comprising a filter provided in a path connecting an exhaust side of said suction means to said blowing means. A printing device comprising the sheet stacking device according to any one of claims 1 to 12 .

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