JP2022050872A - Sheet feeder - Google Patents

Abstract

To provide a sheet feeder capable of reducing chattering noise occurring when a sheet is handled, without damaging the sheet.SOLUTION: A sheet feeder 2 makes stacked sheets P separate from each other when they pass through a pressure-contact area 19 between a pickup roller 12b and a handling member 13, and feeds the sheet P one by one downstream of the pressure-contact area 19. The sheet feeder has an air blowing part 23 for blowing air 24 in the direction of separating the sheet P from a handling member 13 over the sheet P after passing through the pressure-contact area 19, from a downstream side in the feeding direction of the sheet P.SELECTED DRAWING: Figure 5

Description

The present invention relates to a sheet feeding device that feeds sheets.

A paper feeding device is widely used in which the loaded paper is conveyed by a scraper roll and a pickup roll, and the pick-up roll and the handling member separate the loaded paper one by one. In such a paper feeding device, when the paper is handled by the handling member, the paper slips and the handling member vibrates, and the paper to which this vibration is transmitted amplifies the vibration and tends to generate a chattering sound.

Conventionally, as a solution to the above problem, a method of suppressing sound by adding a member for suppressing vibration of a handling member has been known. Although the vibration can be suppressed to some extent by using such a method, the vibration of the handling member is generated and it is difficult to obtain a sufficient effect (for example, Patent Documents 1 and 2).

Further, a method of suppressing the resonance of the paper by providing a guide for bending the paper that has passed through the nip portion toward the paper feed roller side is also disclosed. However, such a method has a problem that damage to the paper such as scratches, folds, and wrinkles is likely to occur (for example, Patent Document 3).

Japanese Unexamined Patent Publication No. 2000-16981 Japanese Unexamined Patent Publication No. 7-1330335 Japanese Unexamined Patent Publication No. 2012-126525

An object of the present invention is to solve the above-mentioned problems and to provide a sheet feeding device capable of reducing chattering noise generated when handling sheets without damaging sheets such as paper.

In order to achieve the above object, the sheet feeding device according to one aspect of the present invention is
In a sheet feeding device that separates the overlapped sheets when passing through the pressure contact portion between the pickup roll and the handling member, and feeds the sheets one by one to the downstream side of the pressure contact portion.
The sheet that has passed through the pressure contact portion is provided with an air blowing portion that blows air in a direction that separates the sheet from the handling member from the downstream side in the feeding direction of the sheet.

According to the present invention, it is possible to reduce the chattering noise generated when the sheets are separated without damaging the sheets such as paper.

FIG. 1 is an explanatory diagram showing a schematic configuration of a printing device including a sheet feeding device according to an embodiment of the present invention. FIG. 2 is a block diagram showing a configuration of a control system in the printing apparatus of FIG. FIG. 3 is an explanatory diagram showing a schematic configuration of the paper feed unit of FIG. FIG. 4 is an enlarged explanatory view showing a pressure contact portion between the pickup roll and the handling member of FIG. 3 in an enlarged manner. FIG. 5 is a plan view of the pressure contact portion of FIG.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. The same or equivalent parts and components are designated by the same or equivalent reference numerals throughout the drawings. However, it should be noted that the drawings are schematic and may differ from the actual ones. In addition, it goes without saying that parts having different dimensional relationships and ratios are included between the drawings.

Further, the embodiments shown below exemplify an apparatus or the like for embodying the technical idea of the present invention, and the technical idea of the present invention describes the arrangement of each component and the like as follows. It is not specific to. The technical idea of the present invention can be modified in various ways within the scope of claims.

FIG. 1 is an explanatory diagram showing a schematic configuration of a printing device including a sheet feeding device according to an embodiment of the present invention, and FIG. 2 is a block diagram showing a configuration of a control system of the printing device shown in FIG. In the following description, the front is the front direction of the paper in FIG. 1 where the user is located. Further, as shown in FIG. 1, the vertical and horizontal directions are defined as the vertical and horizontal directions when viewed from the user. The path shown by the thick line in FIG. 1 is the transfer path R to which the paper P, which is the printing medium, is conveyed. In the following description, upstream and downstream mean upstream and downstream of the transport direction Y of the paper P in the transport path R.

As shown in FIG. 1, the printing apparatus 1 includes a paper feeding unit 2 and a printing unit 3. Further, as shown in FIG. 2, the printing apparatus 1 further includes a control unit 4 for controlling the operation of the paper feeding unit 2 and the printing unit 3.

The paper feeding unit 2 as a sheet feeding device feeds the paper P to the printing unit 3. As shown in FIG. 1, the paper feed unit 2 includes a paper feed table 11, a paper feed roller 12, an intermediate transfer roller 15, and a resist roller 17. Further, as shown in FIG. 2, the paper feed unit 2 further includes a paper feed motor 14, an intermediate transfer motor 16, and a resist motor 18.

The paper feed tray 11 shown in FIG. 1 is loaded with the paper P used for printing, and the paper feed roller 12 is arranged on the upper side thereof. FIG. 3 is an explanatory diagram showing a schematic configuration of the paper feed unit 2. In FIG. 3, the portion of the intermediate transport roller 15 of the transport path R is not shown.

As shown in FIG. 3, the paper feed roller 12 has a scraper roll 12a and a pickup roll 12b. The scraper roll 12a contacts the uppermost portion of the paper P loaded on the paper feed tray 11 and rotates to feed the paper P from the paper feed tray 11. The pickup roll 12b is in pressure contact with the handling plate 13 as a handling member.

When two or more sheets of paper P sent out from the paper feed tray 11 by the scraper roll 12a are double-fed, the first sheet of paper P in contact with the pickup roll 12b at the pressure contact portion 19 between the pickup roll 12b and the handling plate 13. Only is sent downstream from the pressure welded portion 19. The second and subsequent sheets of paper P that do not come into contact with the pickup roll 12b are restricted from moving to the downstream side of the pressure contact portion 19 due to the frictional force generated by the contact with the handling plate 13. Therefore, the paper P passes through the pressure contact portion 19 one by one and is sent to the transport path R on the downstream side of the pressure contact portion 19.

The paper feed roller 12 is rotated by the paper feed motor 14 of FIG. Specifically, the paper feed motor 14 rotates the scraper roll 12a and the pickup roll 12b of FIG. 3 in which a timing belt (not shown) is laid between the shafts in synchronization with each other.

The paper feed motor 14 is connected to the scraper roll 12a and the pickup roll 12b by a one-way clutch (not shown). This one-way clutch transmits only the rotation in the direction of feeding the paper P to the transport path R side from the paper feed motor 14 to the scraper roll 12a and the pickup roll 12b.

A pair of intermediate transport rollers 15 shown in FIG. 1 are arranged on the transport path R on the downstream side of the pressure contact portion 19. Both intermediate transfer rollers 15 nip the paper P that has passed through the pressure contact portion 19 one by one and send it out to the downstream side of the transfer path R. As a result, the paper P is conveyed in the transfer direction Y in the transfer path R. One of the intermediate transfer rollers 15 is rotated by the intermediate transfer motor 16 of FIG.

In this embodiment, in order to facilitate the explanation, a case where the paper feed unit 2 includes a paper feed table 11, a paper feed roller 12, a handling plate 13, and an intermediate transfer roller 15 will be described. However, the present invention is also applicable when the paper feed unit 2 has a plurality of sets of a paper feed table 11, a paper feed roller 12, a handling plate 13, and an intermediate transfer roller 15.

A pair of resist rollers 17 are arranged on the transport path R on the downstream side of the intermediate transport roller 15. The resist roller 17 temporarily stops the tip of the paper P conveyed by the intermediate transfer roller 15 to correct the skew, and then nips the tip of the paper P and feeds it to the printing unit 3. The resist motor 18 of FIG. 2 drives the resist roller 17 of FIG.

The printing unit 3 prints on the paper P while conveying the paper P fed by the paper feeding unit 2 on the transport path R on the downstream side of the resist roller 17. In the present embodiment, the printing unit 3 includes a belt transport unit 21 and an inkjet head unit 22.

The belt transport unit 21 sucks and holds the paper P conveyed by the resist roller 17 on the belt and conveys it. When the roller on which the belt of the belt transport unit 21 is hung is driven by a motor (not shown), the belt is rotated and the paper P on the belt is conveyed.

The inkjet head unit 22 is arranged above the belt transport unit 21. The inkjet head unit 22 has a plurality of line-type inkjet heads in which a plurality of nozzles are arranged in a direction (front-back direction) substantially orthogonal to the transport direction Y of the paper P. The inkjet head unit 22 prints an image by ejecting ink from the nozzles of each inkjet head onto the paper P conveyed by the belt transport unit 21.

The control unit 4 controls the operation of each unit of the printing apparatus 1. The control unit 4 includes a CPU, RAM, ROM, and the like.

Specifically, the control unit 4 feeds the paper P to the printing unit 3 by the paper feeding unit 2 of the paper feeding unit 2, and the printing unit 3 conveys the paper P by the belt conveying unit 21 while the inkjet head unit. 22 controls to eject ink and print on paper P.

When the tip of the paper P transported by the intermediate transport roller 15 hits the resist roller 17, the control unit 4 then waits until a specified amount of slack is formed on the tip side of the paper P to be continuously transported by the intermediate transport roller 15. , The resist roller 17 is kept stopped. When a specified amount of slack is formed on the tip end side of the paper P, the control unit 4 decelerates and stops the intermediate transfer roller 15 and then drives the resist roller 17.

By the way, in the paper feeding unit 2, the paper P sent out one by one by the pickup roll 12b moves while rubbing on the surface of the handling plate 13 when passing through the pressure contact portion 19 with the handling plate 13. This movement causes a stick-slip phenomenon in which the handling plate 13 repeatedly contacts and separates from the paper P, and the handling plate 13 self-excited and vibrates, and the vibration is transmitted to the paper P. At the tip of the paper P that has passed through the pressure contact portion 19 and has become a free end, the self-excited vibration transmitted from the handling plate 13 is amplified by resonance, and a vibration sound called chattering sound is generated.

That is, in the paper feed unit 2, every time the paper feed roller 12 conveys the paper P, the paper P passing through the pressure contact portion 19 makes a loud chattering noise and noise is generated.

Therefore, in the printing apparatus 1 of the present embodiment, the fan 23 shown in FIG. 4 blows the air 24 onto the back surface of the paper P that has passed through the pressure contact portion 19. Specifically, the air 24 from the fan 23 is blown from the downstream side to the upstream side in the transport direction Y of the paper P on the back surface of the portion of the paper P that has passed the pressure contact portion 19 in contact with the handling plate 13. The fan 23 is driven by the fan motor 25 shown in FIG. The drive of the fan motor 25 is controlled by the control unit 4.

As shown in FIG. 5, the fan 23 of FIG. 4 is arranged between two guide plates 26 that guide the paper P sent out by the scraper roll 12a to the pressure contact portion 19. Each guide plate 26 is arranged on both sides of the pressure contact portion 19 in a direction (front-back direction) substantially orthogonal to the transport direction Y of the paper P. The air 24 from the fan 23 is sprayed onto the back surface portion of the paper P that has passed through the pressure contact portion 19.

The paper P that has passed through the pressure contact portion 19 is pressed against the pickup roll 12b by the air 24 from the fan 23. Therefore, the paper P that has passed through the pressure contact portion 19 is separated from the handling plate 13, and the contact area with the handling plate 13 is reduced. Therefore, the section in which the paper P passing through the pressure contact portion 19 moves while rubbing on the surface of the handling plate 13 is reduced, and the handling plate 13 is less likely to cause self-excited vibration. Therefore, the chattering noise generated in the paper P due to the vibration transmitted from the handling plate 13 can be suppressed, and the noise when the paper feed roller 12 of the paper feed unit 2 conveys the paper P can be suppressed.

When the direction of the paper P is changed by the guide member physically brought into contact with the paper P passing through the pressure contact portion 19 and the paper P is separated from the handling plate 13, the paper P is bent due to the contact with the guide member. May be damaged.

Further, when a jam occurs on the paper P, it is conceivable to collect the jammed paper P from the paper feed tray 11 side, which is relatively easier to approach than the printing unit 3 side. Also in that case, since the guide member is arranged close to the peripheral surface of the pickup roll 12b, there is a possibility that the paper P cannot be collected because it is caught by the guide member.

On the other hand, in the printing apparatus 1 of the present embodiment, since the paper P is separated from the handling plate 13 by the air 24 from the fan 23, the paper P is not bent toward the pickup roll 12b by using the guide member. It is possible to make it difficult to damage the paper P such as scratches, me, and wrinkles.

According to the printing apparatus 1 of the present embodiment described above, the air 24 from the fan 23 is applied to the back surface of the paper P that comes into contact with the handling plate 13 of the pressure contact portion 19 that feeds the paper P one by one from the paper feed table 11. The paper P is sprayed to separate the paper P from the separating plate 13. Therefore, it is possible to reduce the chattering noise generated during paper handling without damaging the paper P.

In the present embodiment, the case where the paper feed roller 12 has the scraper roll 12a and the pickup roll 12b has been described, but the present invention also describes the case where the paper feed roller 12 is configured by a single roller. Is applicable.

Further, in the present embodiment, the case where the paper feed unit 2 has the paper feed roller 12 and the intermediate transfer roller 15 has been described, but the present invention also describes a sheet feeding device having a configuration in which the intermediate transfer roller 15 is omitted. Is applicable. In that case, the paper feed roller 12 also serves as the intermediate transport roller 15, and the paper P is conveyed until a slack is formed at the tip of the paper P that has reached the resist roller 17.

Further, in the present embodiment, the printing device 1 has been described as an inkjet printing device, but the method is not limited to this, and any sheet feeding device that supplies paper loaded on a paper feed table one by one can be used. The present invention can also be applied to different printing devices. For example, the present invention can be applied to a sheet feeding device of an inkjet printing device such as an electrophotographic method, a stencil printing method, and a thermal transfer type.

Further, in the present embodiment, the sheet feeding device integrally incorporated in the printing device has been described as an example, but the present invention can also be applied to a sheet feeding device independent of the printing device. Further, the sheet fed by the sheet feeding device may be a web-shaped sheet, and is not limited to the paper P of the present embodiment.

As described above, the present invention is not limited to the above-described embodiment, and at the implementation stage, the components can be modified and embodied within a range that does not deviate from the gist thereof. In addition, various inventions can be formed by an appropriate combination of the plurality of components disclosed in the above-described embodiment. For example, some components may be removed from all the components shown in the embodiments.
[Additional Notes]
The embodiments described above disclose the inventions of the following aspects.

That is, as an invention of one aspect,
In a sheet feeding device that separates the overlapped sheets when passing through the pressure contact portion between the pickup roll and the handling member, and feeds the sheets one by one to the downstream side of the pressure contact portion.
The sheet that has passed through the pressure contact portion is provided with an air blowing portion that blows air in a direction that separates the sheet from the handling member from the downstream side in the feeding direction of the sheet.
The sheet feeder is disclosed.

According to the invention according to the above aspect, it is possible to reduce the chattering noise generated when the sheet is separated without damaging the sheet such as paper.

1 Printing device 2 Paper feeding unit (sheet feeding device)
3 Printing unit 4 Control unit 11 Paper feed stand 12 Paper feed roller 12a Scraper roll 12b Pickup roll 13 Handling plate (handling member)
14 Paper feed motor 15 Intermediate transfer roller 16 Intermediate transfer motor 17 Resist roller 18 Resist motor 19 Pressure welding part 21 Belt transfer part 22 Inkjet head part 23 Fan (air blowing part)
24 Air 25 Fan motor 26 Guide plate P Paper (sheet)
R Transport route Y Transport direction

Claims (1)

In a sheet feeding device that separates the overlapped sheets when passing through the pressure contact portion between the pickup roll and the handling member, and feeds the sheets one by one to the downstream side of the pressure contact portion.
The sheet that has passed through the pressure contact portion is provided with an air blowing portion that blows air in a direction that separates the sheet from the handling member from the downstream side in the feeding direction of the sheet.
Sheet feeder.

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