JPH11262893A - Paper sheet cutting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To perform good cutting operation without causing offset or lifting of a paper sheet when cutting edges cut the paper sheet while being moved to the cross direction of the paper sheet. SOLUTION: As a paper sheet holddown member 54 is separated from a guide member 32 to form paper a sheet carrying passage 11 during non-cutting operation when a cutting edge holder 36 is located near a standby position, no trouble occurs in carrying a paper sheet 5. As the paper sheet holddown member 54 is displaced to contact the guide member 32 to hold the sheet 5 on the guide member 32 during transition to cutting operation when the cutting edge holder 36 runs out of the standby position, cutting edges 33, 34, if cutting while being moved to the cross direction of the paper sheet, restrict the movement of the sheet 5 to do stable cutting operation. In particular, as it holds the sheet 5 on the guide member 32 near a cutting position C, it can hold the sheet 5 nearer the cutting position C than it hold with a platen roller or the like, thus to avoid inconveniences resulting in lifting or offset of the sheet 5.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a paper cutting device applied to a receipt printer or the like.

[0002]

2. Description of the Related Art In general, many printers, facsimile machines and the like that use long paper such as roll paper are provided with a paper cutting device for cutting a printed paper into an appropriate length. In many cases, the paper cutting device in this case has a mechanism combining a linear plate-shaped movable blade and a fixed blade having a length over the entire width of the paper, but recently, a disk-shaped cutting blade is set to a standby position at a home position. A mechanism that cuts a sheet by moving the sheet from the position in the width direction of the sheet has attracted attention because it can reduce the size and weight.

Here, an example of a printer equipped with a sheet cutting device for cutting a sheet by moving such a cutting blade in the sheet width direction will be described with reference to FIGS. 7 and 8. FIG. In this printer, a receipt / journal printer 1 used in a POS terminal of an ECR (electronic cash register) or POS (point of sale information) system has a slip printing function capable of printing on a sheet such as a slip. Things. Schematically, as shown in FIG. 7, the upper housing 3 is connected to the lower housing 2 so as to be rotatable about a fulcrum 4 and has an openable and closed clamshell type structure. It is a full open type in which the roll paper transport path can be completely opened by rotating and opening the body 3 upward.

In such a receipt / journal printer 1, the left side functions as a receipt printer area and the right side functions as a journal printer area when viewed from the near side in the sheet discharging direction. A storage unit (not shown) for storing a receipt roll paper 5 is provided in a receipt printer area in the lower housing 2. As shown in FIG. 8A, a roller pair of a transport roller 6 and a pinch roller 7, a platen 8 serving as a guide,
A predetermined bent sheet conveying path 11 is formed through a pair of rollers including conveying rollers 9 and 10, and the sheet is continuous with a receipt issuing port 13 exposed on the POS terminal surface through a sheet cutting device 12. The journal printer area also has a paper transport path basically similar to that of the journal roll paper 14, but is not provided with a paper cutting device. Instead, a roll for winding the printed roll paper 14 is provided. Picking device 15
Is provided. The platen 8 is formed continuously from the receipt printer area to the journal printer area. A printing unit 17 is formed by the platen 8 and the inkjet head 16 which is a non-contact serial type print head moving on the platen 8. It is configured.

The ink jet head 16 is mounted on a carrier 20 which is guided by a guide rail 18 and a carrier shaft 19 in the upper housing 3 and is capable of reciprocating in the left-right direction (the direction orthogonal to the paper transport direction). At the time of full opening of the platen 3, the platen 8 is opened together with the upper housing 3 so that the upper surface of the platen 8 is largely opened. The upper housing 3 is also provided with a carrier motor 21 that can rotate forward and backward, and a carrier belt 22 that is rotationally driven by the carrier motor 21 is stretched across the left and right directions. The carrier 20 is connected to a part of the carrier belt 22, and has a structure in which the carrier 20 reciprocates in the left-right direction according to the driving of the carrier motor 21. As a result, the inkjet head 16 mounted on the carrier 20 can perform a serial printing operation on the roll papers 5 and 14 conveyed by the respective roller pairs on the platen 8.

The receipt / journal printer 1 is provided with a slip printing function for printing on a sheet 23 such as a slip. This slip printing function is to share the printing section 17 over the entire area of the receipt printer area and the journal printer area, and a sheet insertion port 24 is formed on the front side of the printing section 17 in the horizontal direction. A feed roller 25 is provided between the printing unit 17 and the sheet insertion port 24.
And a pinch roller 27 pressed by the spring 26 toward the feed roller 25, and a feed roller pair formed by the feed roller 28 and the pinch roller 30 pressed by the spring 29 toward the feed roller 28. Is provided.

When the sheet paper 23 is inserted between the feed roller 28 and the pinch roller 30 from the sheet insertion port 24, the feed roller pair is rotated in the sheet feeding direction by a drive system (not shown), and Is fed and conveyed to the printing unit 17 side. Thereby, the ink jet head 1
6 can be received. When printing on the sheet paper 23 is completed, the rotation direction of the feed roller pair is switched to the return direction, and the printed sheet paper 23 is returned and conveyed to the near side, and is issued as a slip from the sheet insertion slot 24.

Next, the paper cutting device 12 provided immediately before the receipt issuing port 13 in the receipt printer area will be described. As shown in FIG. 9, for example, the sheet cutting device 12 is configured based on a cutter frame 31 fixed to the lower housing 2 or the like. This cutter frame 31
Is provided with a guide member 32 in the form of a horizontal flat plate having a length equal to or longer than the entire width of the receipt roll paper 5 and forming a part of the paper transport path 11. Further, a pair of disk-shaped cutting blades 33 and 34 are provided which rotate while moving in the sheet width direction along the receipt issuing side end surface of the guide member 32 and cooperate with each other to cut the roll paper 5. . These cutting blades 33 and 34 are rotatably held by a cutting blade holder 36 movably provided along a guide 35 of the cutter frame 31. The upper cutting blade 3 is provided in the cutting blade holder 36.
A protective cover 37 is provided so that 3 is not exposed. Further, the cutting blades 33 and 34 are rotated on the shafts of the cutting members 33 and 34 by frictional sliding on the guide member 32 to be rotated.
Rubber bodies 38 and 39 for rotating the unit 34 together are also attached.

A drive cam 40 is used to reciprocate the cutting blade holder 36 holding the cutting blades 33 and 34 in the paper width direction. The drive cam 40 is formed such that a spiral guide groove 41, which is followed by a boat-shaped slider 36 a provided on the cutting blade holder 36, is formed endless at an end on a drive shaft 42 and is folded back and crosses back and forth. It is formed on the peripheral surface, and is rotationally driven through a motor gear 44 and a drive gear 45 under one-way drive by a drive motor 43. Thus, when the drive motor 43 rotates and the drive shaft 42 rotates at the home position of the cutting blade holder 36 detected by the home position sensor 46, the cutting blade is engaged by the guide groove 41 and the slider 36a. The holder 36 moves in the paper width direction. At this time, the rubber members 38 and 39 frictionally slide on the guide member 32 with the movement of the cutting blade holder 36, so that the cutting blade 3
The cutting blades 33 and 34 also move while rotating, and the roll paper 5 is sequentially cut at the cutting position C by the cooperation of these cutting blades 33 and 34. When the cutting of the roll paper 5 is completed and the slider 36a reaches the end of the guide groove 41, the moving direction of the cutting blade holder 36 is switched to the reverse direction (return direction) toward the home position, and finally. When the cutting blade holder 36 returns to the home position and is detected by the home position sensor 46, it stops and waits.

[0010]

However, in the case of such a paper cutting device 12, as can be seen from FIG. 9, the movement of the roll paper 5 on the guide member 32 during cutting by the cutting blades 33 and 34 is restricted. Guide member 32
Cutting blades 33, 34 floating or moving from the surface
May be displaced in the direction of movement. If the roll paper 5 floats or shifts in this way, the cutting operation is not performed well, and a cutting defect such as a jam or an oblique cut accompanying the cutting operation occurs.

Particularly, in the case of the receipt / journal printer 1 to which the slip printing function is added as described above, FIG.
As shown in (a) and the like, a unique transport system member (feed roller) that horizontally reciprocates the sheet paper 23 toward the print unit 17 from the print unit 17 in the receipt printer area to the paper transport path 11 on the paper discharge side. 25, 28, etc.), the paper cutting device 12 cannot be disposed immediately after the printing unit 17, and the like. Therefore, the head position A of the printing unit 17 and the cutting position C of the paper cutting device 12 are restricted. Will be separated from each other. As a result, the roll paper 5 is regulated at the position closest to the cutting position C by a pair of rollers, that is, the conveying rollers 9 and 10. The movement of the paper 5 cannot be regulated. Also, in the case of receipt printing, FIG.
As shown in FIG. 7, before the roll paper 5 is cut, a logo printing mechanism 48 such as a store name is printed on the header portion of the receipt to be issued next by the logo printing mechanism 48.
And the cutting position C, it is necessary to have a horizontal portion in the paper transport path 11 on the upstream side of the cutting position C. In addition, the ink printed by the inkjet head 16 in the printing unit 17 is cut as much as possible before cutting. It is necessary to provide an open space before the cutting position C even when drying. The transport rollers 9 and 10 are in contact with both sides of the roll paper 4 outside the receipt printing area to feed the paper.

Further, even if the slip printing function is not added and the paper cutting device 12 can be arranged at a position closer to the position A of the printing unit 17,
In the case of a configuration using a non-contact serial type print head such as No. 6, the paper pressing force of the printing unit 17 is weak, and the function of preventing floating and paper misalignment is hardly performed. In particular, in the case of a serial printer, when the paper is cut, the print head such as the ink jet head 16 returns to the home position (standby position) outside the paper, so that the roll paper 5 on the guide member 32 tends to be in a free state.

By the way, in the case of a printer using a close-contact line type print head such as a thermal printer, a paper cutting device is disposed at a position immediately after a printing unit formed by a line type print head and a platen roller. Since the paper can be cut in a state where the paper is pressed at the printing section near the target cutting position, it can be said that the floating or displacement of the paper during the cutting movement by the cutting blade is relatively small. However, even with such a contact line type print head, the paper cannot be pressed at a position closer to the cutting position than the radius of the platen roller, and the paper pressing function for the cutting operation is not necessarily sufficient. .

Accordingly, the present invention provides a sheet cutting apparatus which can perform a good cutting operation without causing the sheet to float and the sheet to shift when the cutting blade cuts the sheet while moving in the sheet width direction. The purpose is to provide.

[0015]

According to the first aspect of the present invention,
A sheet cutting device for cutting a sheet by reciprocating a cutting blade holder on which a cutting blade is mounted in a sheet width direction from a standby position, wherein a guide member for guiding the sheet to a cutting position by the cutting blade, and the cutting blade holder A movable member that is displaced according to whether or not the cutting blade is located near the standby position, and the cutting blade holder is disposed near the guide member near the cutting position by the cutting blade and the cutting blade holder is positioned near the standby position. A paper pressing member that forms a paper transport path separated from the guide member in conjunction with the movable member, and that contacts the guide member in conjunction with the movable member when the cutting blade holder deviates from near the standby position. And with.

Therefore, when the cutting blade holder is located near the standby position and does not perform the cutting operation, the sheet pressing member is separated from the guide member to form a sheet conveying path, so that the sheet conveying operation is not hindered. When the cutting blade holder is disengaged from the vicinity of the standby position and shifts to the cutting operation, the paper pressing member is displaced so as to contact the guide member and presses the paper onto the guide member, so that the cutting blade moves in the paper width direction. Even when cutting is performed, the movement of the sheet is regulated, so that stable cutting can be performed. In particular, since the sheet is pressed on the guide member near the cutting position, the sheet can be pressed at a position closer to the cutting position than when the sheet is pressed by a platen roller or the like, and the sheet does not float or shift.

According to a second aspect of the present invention, the movable member of the paper cutting device according to the first aspect is displaced in a direction away from the guide member by the cam action of the cutting blade holder located near the standby position. Therefore, a reliable displacement operation of the movable member according to the position of the cutting blade holder can be ensured, and the paper pressing member can be appropriately linked.

According to a third aspect of the present invention, at least a part of the sheet pressing member of the sheet cutting device according to the first aspect of the present invention has a spring property and elastically contacts and separates from the guide member. Therefore, the state of pressing the sheet by the sheet pressing member is stabilized.

According to a fourth aspect of the present invention, the sheet pressing member of the sheet cutting apparatus according to the first aspect has a plurality of projections at portions that come into contact with and separate from the guide member. Therefore, it is possible to secure the pressing state of the sheet, particularly, the pressing state that can prevent the sheet from being shifted due to the cutting operation, by the protrusion shape.

According to a fifth aspect of the present invention, the sheet pressing member of the sheet cutting device according to the first aspect has a star wheel rotatably held in the sheet conveying direction and coming into contact with and separating from the guide member. Therefore, the pressing state of the sheet, particularly the pressing state that can prevent the sheet from being shifted due to the cutting operation, can be ensured by the star wheel, and the sheet comes into contact with the sheet during the non-cutting operation forming the sheet transport path. Even if there is, the starwheel rotates following and becomes point-contact, so especially in the case of a printer that uses ink such as an ink jet printer, the ink rubs the printing surface where the ink does not dry. Can also be avoided.

[0021]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described with reference to FIGS. The paper cutting device 51 of the present embodiment is applied to a receipt printer in the receipt / journal printer 1 to which a slip printing function is added, and the same parts as those shown in FIGS. 7 to 9 are denoted by the same reference numerals. It is shown and the description is omitted. Therefore, as the cutting mechanism using the cutting blades 33 and 34, the mechanism shown in FIG. 9 and the like is used as it is.

In this embodiment, a shaft 52 is rotatably mounted on the cutter frame 31 so as to be positioned upstream of the cutting position C in the sheet transport direction as shown in FIG. A movable member 53 and a paper pressing member 54 are fitted on the shaft 52 and fixed by integral molding or the like. Therefore, the movement (rotational displacement) of the paper pressing member 54 is configured to interlock with the movement of the movable member 53 via the shaft 52. Here, the movable member 53 rotates and displaces with the shaft 52 depending on whether the cutting blade holder 36 is located near the home position, and moves in the left-right direction (the direction perpendicular to the sheet conveying direction). The blade holder 36 is formed so as to protrude into a cam structure so as to interfere with the top cam-shaped portion of the protective cover 37 near the home position. The paper pressing member 54 on the paper path is formed to protrude so as to freely contact and separate from the upper surface of the guide member 32 at a position as close as possible to the cutting position C as long as the movement of the cutting blade holder 36 is not hindered. ing. Such a paper pressing member 54 is pressed and urged from the upper surface side by a compression spring 55 in a direction in which it comes into contact with the guide member 32. Thus, when the cutting blade holder 36 is located at a position away from the home position, the sheet pressing member 54 is brought into contact with the guide member 32 (roll paper 5) by receiving the urging force of the compression spring 55. When 36 is at the home position, the cutting blade holder 36 pushes up the movable member 53 to separate the paper pressing member 54 from the upper surface of the guide member 32 against the urging force of the compression spring 55, and The paper transport path 11 is formed between them.

In such a configuration, during the printing operation on the roll paper 5 by the ink jet head 16, the cutting blade holder 36 is at the home position. At this time, since the top portion of the protective cover 37 of the cutting blade holder 36 is located at a position corresponding to the movable member 53 and the movable member 53 is pushed up by the cam action, as shown in FIG. The member 54 is also separated from the guide member 32 surface. As a result, the paper transport path 11 is secured, so that the transport state of the roll paper 5 during the printing operation is not hindered.

After the printing on the roll paper 5 is completed, when the desired cutting position is transported to the paper cutting device 12, the transport of the roll paper 5 is stopped, and the driving motor 43 is driven to start the cutting operation. . That is, the cutting blade holder 36 starts moving in the cutting direction from the home position in accordance with the drive of the drive cam 40. When the cutting blade holder 36 moves to a position outside the vicinity of the home position, the top portion of the protective cover 37 moves smoothly according to the cam shape. It will come off the member 53. Thus, as shown in FIG. 1B, the leading end side of the paper pressing member 54 receiving the urging force of the compression spring 55 is displaced so as to contact the roll paper 5 on the guide member 32. Thus, the roll paper 5 is pressed by the leading end of the paper pressing member 54 in the vicinity of the cutting position C, and its movement is regulated. In such a state, the cutting blade holder 36 moves to the roll paper 5 side, and the cutting operation by the cooperation of the cutting blades 33 and 34 is started. At this time, since the roll paper 5 is pressed by the paper pressing member 54 in the vicinity of the cutting position C, it does not float from the surface of the guide member 32 or shift in the cutting direction due to the movement of the cutting blades 33 and 34. It can be cut well. That is, a stable cutting operation is performed.

After the cutting, the moving direction of the cutting blade holder 36 is switched to the returning direction to the home position according to the drive cam 40. When the cutting blade holder 36 returns to the vicinity of the home position again, the movable member is moved by the cutting blade holder 36. Since the sheet 53 is pushed up, the sheet pressing member 54 is also displaced so as to be separated from the guide member 32. As a result, the paper transport path 11 is secured, and there is no problem in transporting the next roll paper 5.

As described above, according to the present embodiment, in the paper cutting device 51, the paper pressing member 54 for pressing the roll paper 5 onto the guide member 32 near the cutting position C by the cutting blades 33 and 34 is used. Since the roll paper 5 is provided, the cutting operation of the roll paper 5 can be stably performed even if the cutting position C and the transport rollers 9, 10 and the like are apart from each other due to some restrictions.

However, the method of this embodiment is effective not only for the receipt / journal printer 1 to which the slip printing function is added as described above, but also for the printing method. The present invention is not limited to a printer using a print head of a type, but is also effective to a printer using a print head of a contact line type such as a thermal printer. That is, as schematically shown in FIG.
Assuming that the cutting position by the sheets 3 and 34 is C, the pressing position by the paper pressing member 54 is P, and the printing position (clamping position) by the print head 61 and the platen roller 62 is P ', the printing position P' is the cutting position C. On the other hand, it is not possible to approach the position closer than the radius of the platen roller 62, but according to the present embodiment, the pressing position P can be closer to the cutting position C, so that the cutting operation at the cutting position C is more stable. Can be done.

FIG. 4 shows a modification of the sheet pressing member 71.
The paper pressing member 71 has a thinly formed springy member 72 integrally formed at the leading end for pressing the roll paper 5 onto the guide member 32. Therefore, according to this modification, the paper pressing member 71 elastically comes into contact with and separates from the guide member 32 by the spring member 72. As a result, the pressing state of the roll paper 5 by the paper pressing member 71 at the time of cutting the paper becomes more stable.

FIG. 5 shows another modified example of the sheet pressing member 73. The paper pressing member 73 guides the roll paper 5 to the guide member 32.
The tip part pressed upward is formed in a sawtooth shape, and has a shape having a plurality of protruding parts 73a with a sharp tip. Therefore, according to this modification, at the time of a cutting operation involving movement by the cutting blades 33 and 34, the leading end portion pressing the roll paper 5 on the guide member 32 is the protruding portion 73a. 5 can be reliably prevented, and the cutting operation is more stable.

FIG. 6 shows still another modification. In this modification, first, the movable member 53 and the paper pressing member 54 are formed integrally. Further, on the paper pressing member 54 side, a plurality of star wheels 74 that are rotatably held along the transport direction of the roll paper 5 and come into contact with and separate from the roll paper 5 on the guide member 32 are provided. These star wheels 74 are formed by forming a thin disk-shaped peripheral surface with a large number of tooth shapes with sharp tips. When the star wheels 74 are separated from the guide member 32, a paper transport path is formed between the guide member 32 and the star wheel 74. 11 are formed.

Therefore, according to this modification, the roll paper 5
In the holding state, in particular, the paper shift due to the cutting operation can be reliably prevented by the star wheel 74 as in the case of the projection 73a. Further, at the time of the non-cutting operation forming the paper transport path 11, the roll paper 5 is
Even if it touches the 4 side, the star wheel 7
4 follows and improves the transportability and becomes point-contact. Therefore, especially in the case of a printer using ink such as an ink jet printer, the ink rubs on the printing surface where the ink does not dry. Problems can also be avoided.

In this embodiment and the modifications thereof, the sheet is cut by the cooperation of the disc-shaped cutting blades 33 and 34. However, the present invention is not limited to such a method, and for example, a guide member may be used. The same method can be applied to a system in which the paper discharge side edge of the sheet 32 is a fixed blade and the sheet is cut by cooperation of the disk-shaped cutting blade 33 and the fixed blade.

[0033]

According to the first aspect of the present invention, when the cutting blade holder is located near the standby position and does not perform a cutting operation, the sheet pressing member is separated from the guide member to form a sheet conveying path. Therefore, when the cutting blade holder comes out of the vicinity of the standby position and shifts to the cutting operation, the paper pressing member is displaced so as to abut the guide member and presses the paper onto the guide member. Even when cutting is performed while the cutting blade moves in the sheet width direction, the movement of the sheet is regulated, so that a stable cutting operation can be performed. In particular, the sheet is pressed onto the guide member near the cutting position. Therefore, the sheet can be pressed at a position closer to the cutting position than when the sheet is pressed by a platen roller or the like, and a problem that the sheet floats or shifts can be avoided.

According to the second aspect of the present invention, the movable member of the paper cutting device according to the first aspect is displaced in a direction away from the guide member by receiving the cam action of the cutting blade holder located near the standby position. Thus, a reliable displacement operation of the movable member according to the position of the cutting blade holder can be ensured, and the paper pressing member can be appropriately linked.

According to the third aspect of the present invention, at least a part of the sheet pressing member of the sheet cutting device according to the first aspect of the present invention has a spring property and is elastically connected to and separated from the guide member.
The pressing state of the sheet by the sheet pressing member can be further stabilized.

According to the fourth aspect of the present invention, since the paper pressing member of the paper cutting device according to the first aspect has a plurality of projections at the portions that come into contact with and separate from the guide member, the paper pressing state, particularly cutting The pressing state that can prevent the sheet from being shifted due to the operation can be easily ensured by the projection shape.

According to the fifth aspect of the present invention, since the paper pressing member of the paper cutting device according to the first aspect has the star wheel rotatably held in the paper conveying direction and coming into contact with and separating from the guide member. In addition to the paper pressing state, in particular, the pressing state that can prevent the paper misalignment due to the cutting operation can be secured by the star wheel, and the paper may contact during the non-cutting operation forming the paper transport path. Even if there is, the star wheel rotates following and becomes point contact, so especially in the case of a printer that uses ink such as an ink jet printer, there is also a problem that the ink rubs the printing surface that does not dry and contaminates Can be avoided.

[Brief description of the drawings]

1A and 1B show an embodiment of the present invention, wherein FIG. 1A is a schematic side view at the time of a non-cutting operation, and FIG. 1B is a schematic side view at the time of a cutting operation.

FIG. 2 is a schematic perspective view showing a sheet cutting device.

FIG. 3 is a schematic view conceptually showing;

FIG. 4 is a perspective view showing a modification.

FIG. 5 is a perspective view showing another modification.

FIG. 6 is an inverted perspective view showing still another modified example.

FIG. 7 is a schematic perspective view of a receipt / journal printer showing a conventional example.

FIG. 8A is a schematic side view of a receipt printer portion, and FIG. 8B is a plan view showing a roll paper for receipt.

FIG. 9 is a schematic perspective view showing the paper cutting device.

[Explanation of symbols]

 5 Paper 11 Paper transport path 32 Guide member 33, 34 Cutting blade 36 Cutting blade holder 53 Moving member 54 Paper pressing member 71 Paper pressing member 73 Paper pressing member 73a Projection shape 74 Star wheel

Claims (5)

[Claims] 1. A sheet cutting device for cutting a sheet by reciprocating a cutting blade holder on which a cutting blade is mounted in a sheet width direction from a standby position, and guiding the sheet to a cutting position by the cutting blade. A movable member that is displaced according to whether or not the cutting blade holder is located near a standby position;
A sheet conveyance path separated from the guide member in conjunction with the movable member when the cutting blade holder is located near the standby position and the cutting blade holder is located near the standby position near the cutting position by the cutting blade. A sheet holding member formed to contact the guide member in conjunction with the movable member when the cutting blade holder comes off the vicinity of a standby position. 2. The paper cutting apparatus according to claim 1, wherein the movable member is displaced in a direction away from the guide member by a cam action of the cutting blade holder located near the standby position. 3. The sheet cutting apparatus according to claim 1, wherein at least a part of the sheet pressing member has a spring property and is elastically connected to and separated from the guide member. 4. The paper cutting device according to claim 1, wherein the paper pressing member has a plurality of protrusions at a portion that comes into contact with and separates from the guide member. 5. The sheet cutting device according to claim 1, wherein the sheet pressing member has a star wheel rotatably held in the sheet conveying direction and coming into contact with and separating from the guide member.