JP2002154725A - Ink jet printer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent a paper sheet from meandering during transfer and print on printing media with different widths in the same positional relation even if a dot impact print head is not moved. SOLUTION: A drive roller 5 and a pressing roller 6 are disposed so that the longitudinal center parts thereof are aligned with each other. The lateral position of paper 2 is restricted by lateral restriction guides 30a and 30b so as to match the longitudinal center parts of the drive roller 5 and the pressing roller 6. Also, the dot impact print head is disposed so as to match the lateral center position of the paper 2.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink jet printer capable of performing printing on a long print medium, and more particularly to an ink jet printer capable of transporting a print medium without meandering.

[0002]

2. Description of the Related Art Ink jet printers perform printing by spraying liquid ink onto paper, and have the advantage that the size of the apparatus can be reduced and high quality printing can be performed. When a long sheet of paper that needs to be cut, such as roll paper or fold paper, is used as a print medium of such an ink jet printer, it is common to perform printing before cutting the paper in order to improve print quality. For that purpose, it is necessary to transport a long sheet to the print head without meandering. In general, a drive roller unit having a drive roller and a pressure roller that presses the drive roller is used to transport a long sheet to the print head.

FIG. 5 shows a drive roller unit (drive roller unit) used in a general ink jet printer.
FIG. Drive roller unit 114 shown in FIG.
Are one drive roller 105 and six pressure rollers 1
06. The cylindrical drive roller 105 is driven to rotate by a motor (not shown). Further, the six cylindrical pressing rollers 106 are arranged such that the driving rollers 10 are opposed to the driving roller 105 with the paper 102 interposed therebetween.
5 are juxtaposed. 6 pressure rollers 106
Are arranged substantially uniformly over the entire length region of the drive roller 105. The pressure roller 106, which is a driven roller, is rotatably supported at one end of the support member 107. The support member 107 is rotatable around a fulcrum (not shown) at the other end. The paper 102 is driven by the driving roller 105 and the pressure roller 1.
06 and conveyed to the print head side.

[0004] Further, an ordinary ink jet printer has a guide mechanism upstream of the drive roller unit in order to regulate the position of a long sheet in the width direction. For example, in the case of an ink jet printer having a drive roller unit 114 as shown in FIG. 5, the guide mechanism includes a movable wall slidable in the width direction of the paper 102 and a fixed wall (both not shown) opposed thereto. It is common to have In the case of such an ink jet printer, the moving wall is slid to a position corresponding to the width of the paper 102 while pressing the moving wall against one end of the paper 102, so that the other end of the paper 102 is fixed to the fixed wall. Move to contact position. That is, the paper 102 is positioned so that the other end of the paper 102 is always at the same position regardless of its width. For example, in the example of FIG. 5, the fixed wall is fixed at a position corresponding to the dashed line L in the figure.
02 has the width (in FIG. 5, the width is "A", "
B "and" C "are drawn), regardless of whether the sheet is drawn).

As described above, by using a drive roller unit having a drive roller and a pressure roller in an ink jet printer, it is possible to reliably supply paper to a print head. In addition, by using a guide mechanism having a fixed wall and a moving wall in an ink-jet printer, it is possible to realize paper alignment in the width direction with a simple mechanism in which the moving wall slides in the width direction of the paper. Has become.

[0006]

However, in the ink jet printer having the above-mentioned guide mechanism in which the paper is positioned so that the widthwise end of the paper is always aligned at the same position regardless of the width, the width of the paper depends on the width of the paper. The press roller does not press the paper symmetrically with respect to the sheet and the center position in the width direction. For example, in the example of FIG.
When the width dimension of the sheet 10 is C, the pressure roller 106
2 and the center of the sheet 102 in the width direction, but when the width of the sheet 102 is A or B, the pressure roller 106 presses the sheet 102 and the center of the sheet in the width direction symmetrically. Not. As a result, the force applied to the paper 102 becomes uneven with respect to the center in the width direction, and the paper 102 conveyed by the drive roller unit 114 is meandered in the width direction. Significantly deteriorates.

On the other hand, printing of information such as the date and time of printing and a serial number may be required on the back side of the paper (the side on which ink-jet printing is not performed). In many cases, a dot impact printing unit that can perform the printing is used. However, in the ink jet printer having the above-described guide mechanism in which the paper is positioned so that the widthwise end of the paper is always aligned at the same position regardless of the width, the contact position of the dot impact type print head with the paper is changed. Generally, it is shifted from the center position in the width direction. Therefore, a phenomenon occurs in which the paper passing through the print head meanders in the width direction due to the resistance applied to the paper from the print head.
To avoid such a phenomenon, the print head of the dot impact type may be moved in accordance with the width of the paper so that the print head always coincides with the center position in the width direction of the paper. Will be.

SUMMARY OF THE INVENTION Accordingly, it is a primary object of the present invention to provide an ink jet printer capable of preventing a print medium from meandering at a driving roller portion regardless of the width of the print medium.

Therefore, a further object of the present invention is to provide a printing method using a dot impact type print head regardless of the width of the print medium, without moving the dot impact type print head in accordance with the width of the print medium. An object of the present invention is to provide an ink jet printer capable of preventing a print medium from meandering.

[0010]

According to an aspect of the present invention, there is provided an ink jet printer, comprising: a printing unit for performing printing on a long print medium by an ink jet method; A drive roller unit in which a plurality of rollers are arranged so that the print medium can be sandwiched in order to supply the print medium and has at least one region symmetrical in a longitudinal direction; A position regulating unit that regulates the position in the width direction of the printing medium such that the center position in the width direction of the printing medium in the unit is the same regardless of the width of the printing medium and matches the center position of any of the regions. And is characterized by having.

The "region" may be a region corresponding to the entire length of the drive roller portion in the longitudinal direction, or may be a region corresponding to a part of the drive roller portion in the longitudinal direction. Such a region and its center position are substantially innumerable, for example, when the drive roller unit includes only two pairs of rollers having the same length. As shown in FIG. 5, a driving roller 105 having a sufficiently long driving roller portion and a plurality of pressing rollers 106 shorter than the driving roller 105 and having the same shape are provided.
When the rollers 6 are arranged symmetrically with respect to the center of the drive roller 105, each of the central positions in the longitudinal direction of each of the pressing rollers 106 and the central position of the gap between the two pressing rollers 106 is defined in claim 1. It is the center position of the defined area. However, the length of each region along the longitudinal direction of the drive roller 105 becomes longer as the center position is closer to the center position of the drive roller 105. And the driving roller 10
The longer the region along the longitudinal direction of 5, the wider the printing medium can be handled.

That is, according to the first aspect, not only the position in the width direction of the print medium is regulated so that the center position in the width direction of the print medium becomes the same regardless of the width, but also the width direction of the print medium is not limited. The position in the width direction of the print medium is regulated such that the center position coincides with the center position of any region symmetrical with respect to the longitudinal direction of the drive roller unit. Therefore, the rollers included in the drive roller unit are symmetrically pressed against the print medium at the center position in the width direction, and an equal force is applied to both sides of the center position in the width direction of the print medium. Thereby, the print medium hardly meanders during transportation.

The drive roller unit may be one in which only one roller is disposed at a position facing each other, or one in which a plurality of rollers are disposed. Alternatively, the drive roller unit may be one in which only one roller is arranged at one of the positions facing each other and a plurality of rollers are arranged at the other. Further, as the position restricting portion, those having a wall portion for restricting the positions of both ends of the print medium are usually used,
A material having no wall may be used according to the characteristics of the print medium. Further, only one pair of such wall portions may be provided on the upstream side of the drive roller portion, or a plurality of such wall portions may be provided. Further, the position of the drive roller unit may be any position as long as it is on the upstream side of the cutting position of the print medium,
For example, it may be between the printing unit and the cutting position, or between the printing unit and the dot impact print head.

According to a second aspect of the present invention, in the ink jet printer according to the first aspect, the driving roller section includes:
The printing medium is sandwiched only by the two rollers arranged so as to face each other.

According to the second aspect of the present invention, since the print medium is sandwiched by only two rollers disposed so as to face each other in the drive roller section, the number of rollers included in the drive roller section can be minimized. . This makes it possible to easily adjust the position of the roller in the drive roller unit and reduce the manufacturing cost of the drive roller unit. Further, when the printing medium is 3
As in the case of being pinched by two or more rollers, uneven force is not applied to both sides of the center position in the width direction of the print medium due to individual differences between the rollers due to manufacturing errors, so that during transport, Meandering of the print medium can be more effectively suppressed.

According to a third aspect of the invention, there is provided an ink jet printer.
A dot impact print head according to claim 1 or 2, wherein a dot impact print head is arranged at a position corresponding to a center position in the width direction of the printing medium regulated by the position regulating section.

According to the third aspect, since the dot impact print head is arranged at a position corresponding to the center position in the width direction regardless of the width of the print medium, the dot impact print head is moved according to the width of the print medium. Even without this, the print medium will hardly meander due to the resistance applied to the print medium from the dot impact print head.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A preferred embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a diagram showing a schematic configuration of an ink jet printer according to the present embodiment. FIG. 2 is a perspective view illustrating a schematic configuration of the sheet supporting unit according to the present embodiment. FIG. 3 is a front view showing a schematic configuration of the sheet supporting unit shown in FIG. FIG. 4 is a diagram illustrating a schematic configuration of a drive roller unit of the ink jet printer according to the present embodiment.

As shown in FIG. 1, an ink jet printer 1 of the present embodiment includes a paper support unit 10, a dot impact print unit 11, a drive roller unit 14, It has a printing unit 15 and a cutting unit 17.

As shown in FIGS. 2 and 3, the paper supporting unit 10 has a width regulating guide 31a, 31b, paper width regulating guides 32a, 32b, and arms 33a, 33b connecting these. Guides 30a, 30
b, a guide drive mechanism 40 below and supporting the width regulating guides 30a and 30b, and the winding portion 2
and a substantially rectangular parallelepiped storage container 50 (shown by a two-dot chain line in FIGS. 2 and 3) for storing the width regulating guides 30a and 30b and the guide driving mechanism 40 together with the paper 2 having the letter a. .

The storage container 50 is composed of an upper part 50a and a lower part 50b, both of which have a substantially triangular prism shape.
Can be opened and closed by rotating around a horizontal axis at a connection point with the lower portion 50b. When the storage container 50 is opened, the width regulating guides 30a and 30b can be easily accessed from outside, and operations such as loading of the paper 2 into the width regulating guides 30a and 30b can be performed. Can be performed. On the other hand, the storage container 5
When 0 is closed, the paper 2 is shielded from the outside, and the paper 2 is protected from contamination by dust and the like.

A pair of right and left winding portion width regulating guides 31a and 31b each having a substantially L-shape are members for positioning the width direction of the sheet 2 in the winding portion 2a. 2a are opposed to each other so as to be sandwiched from both ends in the width direction. The winding portion width regulating guides 31a and 31b are respectively connected to nuts 41a and 41b which constitute a part of the guide driving mechanism 40, and thereby, as described later, the nuts 41a and 41b
Together with 1b, they can move in opposite directions on the screw shaft 42 on which they are supported. Further, semicircular concave portions 38 are formed at the upper end portions of the winding portion width regulating guides 31a and 31b, respectively.

A drum 37 is gently inserted into a through hole provided at the center of the winding portion 2a of the paper 2,
7 are concave portions 3 of the winding portion width regulating guides 31a and 31b.
8 is supported by an interference fit. This allows
The winding part 2a is rotatable around the drum 37. Therefore, when the paper 2 is pulled to the downstream side, the paper 2 is smoothly unwound from the winding part 2a with the rotation of the winding part 2a.

A pair of left and right paper width regulating guides 32a and 32b each having a substantially L-shape are disposed diagonally above the winding section width regulating guides 31a and 31b, and together with the arms 33a and 33b, the winding section width is regulated. Regulation guides 31a, 3
1b (one on the same side with respect to the width direction of the paper 2). Paper width regulation guide 32a,
Reference numerals 32b are arranged to face each other so as to sandwich the sheet 2 unwound from the winding portion 2a of the sheet 2 from both sides in the width direction.

The guide driving mechanism 40 includes a pair of nuts 4 connected to the winding portion width regulating guides 31a and 31b, respectively.
1a, 41b and a screw shaft 42 having a feed screw portion 43 screwed into a screw hole in the center of the nut 41a, 41b. Both ends of the screw shaft 42 are connected to the lower portion 50 of the storage container.
b. A screw is formed in the feed screw portion 43 that converts the rotational motion of the screw shaft 42 into a linear motion along the screw shaft 42 in a direction in which the nut 41a can move and a region in which the nut 41b can move. I have. Thus, when the screw shaft 42 rotates, the nut 41a and the nut 41b move in opposite directions on the screw shaft 42 in conjunction with each other.

At one end of the screw shaft 42, a transmission gear 44 is arranged. The transmission gear 44 is connected to the lower portion 50 of the storage container.
b, a transmission gear 45 supported on a support shaft 46 protruding from
Is engaged. The transmission gear 45 is connected to the upper portion 50 of the storage container.
While a is within a predetermined angle range with respect to the lower part 50b, the arc-shaped member 47 fixed thereto with the rotation of the upper part 50a
It rotates by meshing with a gear provided on the outer peripheral portion of. In other words, the upper part 50 for opening and closing the storage container.
is rotated, the screw shaft 42 is rotated via the transmission gears 45 and 44, whereby the nuts 41a and 41b supported by the feed screw portion 43 and the winding portion width regulating guide 31 are rotated.
a and 31b move in opposite directions on the screw shaft 42 in conjunction with each other. Specifically, when the storage container 50 is opened, the nut 4
1a, 41b and winding portion width regulating guides 31a, 31b
Move on the screw shaft 42 in a direction away from each other, and when closing the storage container 50, the nuts 41a, 41b and the winding portion width regulating guides 31a, 31b move on the screw shaft 43 in a direction approaching each other.

Further, in the present embodiment, the transmission gear 44
A torque keeper 48 that restricts the torque input to the transmission gear 44 to a predetermined magnitude and transmits the torque to the screw shaft 42 is disposed adjacent to the transmission gear 44.

The sheet 2 unwound from the winding section 2a is subjected to dot impact by a drive roller unit 14 having a drive roller 5 and a pressure roller 6 and a plurality of auxiliary roller pairs 9 for assisting the conveyance of the sheet 2. Printing unit 1
1. The paper is sequentially conveyed to the inkjet printing unit 15 and the cutting unit 17.

As described above, in the ink jet printer 1 of the present embodiment, the paper support unit 10
Accordingly, the position of the sheet 2 in the width direction is regulated.

As shown in FIG. 4, the driving roller unit 1
Reference numeral 4 includes one drive roller 5 and one pressure roller 6 that faces the drive roller 5 with the sheet 2 interposed therebetween. The length of the pressure roller 6 is considerably shorter than the length of the drive roller 5, and both are arranged so that their center positions in the longitudinal direction coincide. Therefore, the drive roller unit 14 having the drive roller 5 and the pressure roller 6
And it is symmetrical with respect to the center position in the longitudinal direction of the pressure roller 6.

As shown in FIG. 1, the drive roller 5 is driven to rotate by a motor 22 controlled by a controller 25. The pressure roller 6, which is a driven roller, is rotatably supported at one end of the support member 7. The support member 7 is rotatable around a fulcrum 7a at the other end. Thereby, an appropriate pressure is applied to the sheet 2 passing between the driving roller 5 and the pressure roller 6.

An auxiliary guide 8 having substantially the same length as the drive roller 5 is arranged at a position close to the pressure roller 6. The auxiliary guide 8 is a substantially rectangular sheet metal member, and has a pressure roller 6 and a support member 7 near its longitudinal center.
Has a rectangular concave portion into which is fitted. Auxiliary guide 8
Has a function of pressing a portion that is not in contact with the pressure roller 6 to the drive roller 5 when the paper 2 having a width larger than the width of the pressure roller 6 is used.

The dot impact print unit 11 has a dot impact print head 12 and a platen 13, and a large number of thin pins provided on the dot impact print head 12 allow the paper 2 to pass through the platen 13 via an ink ribbon. Printing is performed by selectively tapping the above. The dot impact printing unit 11 is used to print additional information such as date and time of printing and a serial number on a surface opposite to a printing surface of the inkjet printing unit 15.

In the present embodiment, the dot impact printing unit 11 is, as shown in FIG.
And a pressure roller 6 at a position corresponding to the longitudinal center position thereof.

The ink jet printing unit 15 prints the paper 2 by jetting liquid ink from the ink jet head 16 for each dot. The ink jet printing unit 15 uses a piezoelectric element to jet ink from the ink jet head, a bubble jet (registered). (Trademark) system or any other system. Here, the inkjet head 16 performs printing by blowing out ink while reciprocating along the width direction of the paper 2.

The cutting unit 17 includes a fixed blade 17a disposed on the same side of the sheet 2 as the dot impact printing unit 11, and a movable blade 17b disposed opposite the fixed blade 17a with the sheet 2 interposed therebetween. have. Both the fixed blade 17a and the movable blade 17b are rectangular blades having a width slightly larger than the width of the paper 2.

Then, the dot impact printing unit 1
The paper 2 on which dot printing and ink-jet printing are sequentially performed after passing through the printing unit 1 and the ink-jet printing unit 15 is cut into a predetermined length by the cutting unit 17 and then discharged from the discharge port 28.

Next, an operation when printing is performed by the ink jet printer 1 according to the present embodiment will be described. In order to perform printing with the ink jet printer 1 according to the present embodiment, the nuts 41a and 41b (and the width regulating guide 30) are set before the sheet 2 is loaded into the sheet supporting unit 10.
It is necessary to adjust the positions of a and 30b) such that the center positions of the two coincide with the longitudinal center positions of the drive roller 5 and the pressure roller 6 of the drive roller unit 14. Adjustment of the position of the nuts 41a and 41b
This is performed manually so that the center positions of the a and 41b coincide with the center position of the pressure roller 6 in the longitudinal direction. In the present embodiment, printing is performed while changing the positions of the nuts 41a and 41b on the assumption that the center positions in the longitudinal direction of the drive roller 5 and the pressure roller 6 coincide with the center position of the printable range of the inkjet head 16. The position adjustment of the nuts 41a and 41b may be performed manually by repeating.

After such adjustment, the paper 2 is loaded into the paper support unit 10. To do this, first, the storage container 50 is opened by rotating the upper portion 50a of the storage container. Then, while the upper part 50a is within a predetermined angle range with respect to the lower part 50b, the arc-shaped member 47 attached inside the upper part 50a meshes with the transmission gear 45, and the transmission gear 45
Rotate counterclockwise. Then, the transmission gear 44 meshing with the transmission gear 45 and the screw shaft 42 rotate, and the nuts 41a and 41b move in a direction away from each other. Accordingly, the width regulation guide 30 including the winding width regulation guides 31a and 31b and the paper width regulation guides 32a and 32b.
a and 30b move to the outermost positions (the positions indicated by the dotted lines in FIG. 3). Therefore, the sheet 2 can be easily refilled.

Then, after the drum 37 is inserted through the center of the winding section 2a of the sheet 2, the sheet 2 is moved to the winding section width regulating guide 31.
a and 31b and the paper width regulating guides 32a and 32b, and the drum 37 is fitted into the recess 38 of the winding width regulating guides 31a and 31b.

Thereafter, the upper portion 50a of the container is rotated to close the container 50. Then, the upper part 50a becomes the lower part 5
While being within a predetermined angle range with respect to 0b, the arc-shaped member 47 attached inside the upper portion 50a meshes with the transmission gear 45, and the transmission gear 45 rotates clockwise in FIG. Then, the transmission gear 44 and the screw shaft 42 meshing with the transmission gear 45 rotate in the directions opposite to the directions when the storage container 50 is opened, and the nuts 41a and 41b move in the directions approaching each other.

When the nuts 41a and 41b start to move in the direction approaching each other, first, the winding portion width regulating guide 31
One of a and 31b contacts the corresponding one end of the winding part 2a, and moves the winding part 2a to the other side while pressing the winding part 2a. And the winding part width regulation guide 31a,
When 31b further moves and both of them come into contact with both ends of the winding portion 2a and sandwich the winding portion 2a,
The winding part 2a stops at that position. At this time, the winding part 2
The center position in the width direction of a is independent of the width of the winding portion 2a.
It always matches the center position of the winding portion width regulating guides 31a and 31b that has been adjusted in advance. Therefore, according to the present embodiment, if the position of each of the width regulating guides 30a and 30b is adjusted in advance, even if the paper 2 has any width, only by closing the storage container 50, the paper 2 The winding portion 2a can be easily and reliably positioned at a predetermined position.
It should be noted that which of the winding portion width regulating guides 31a and 31b first comes into contact with the winding portion 2a is determined depending on the width direction position where the winding portion 2a is arranged.

On the other hand, the winding portion width regulating guides 31a, 31b
Are in contact with both ends of the winding portion 2a, respectively, and at the same time, the sheet width regulating guides 32a and 32b are in contact with both ends of the sheet 2 at portions other than the winding portion 2a, and sandwich the sheet 2 at this portion. At this time, the center position in the width direction of the paper 2 is
Regardless of the width of the sheet 2, the center position of the previously adjusted sheet width regulating guides 32a and 32b (ie, the center position of the winding section width regulating guides 31a and 31b) always matches. As described above, according to the present embodiment, the winding portion width regulating guides 31a and 31b and the sheet width regulating guides 32a and 32
b, the winding portion width regulating guide 31a can be adjusted by simply adjusting the respective positions of the width regulating guides 30a and 30b in advance regardless of the width of the paper 2 having any width. , 31b, the sheet 2 can be easily positioned at a predetermined position in a portion other than the winding section 2a by the sheet width regulating guides 32a, 32b. Thereby, the paper 2 is wound around the winding portion 2a.
The position of the sheet 2 can be improved by positioning the sheet 2 at two positions other than the above.

As described above, even after the paper 2 has been positioned, the upper portion 50a of the storage container rotates to apply a torque to the transmission gear 44. However, in the present embodiment, the torque input to transmission gear 44 is
It is limited to a certain value by 8 and is given to the screw shaft 42. Specifically, when a torque larger than a certain value is applied to the torque keeper 48, the torque keeps running, so that the torque transmitted to the feed screw portion 43 is limited to a certain value. For this reason, in the present embodiment, the winding portion width regulating guides 31a and 31b and the sheet width regulating guide 32a,
An excessive force is not applied to the winding portion 2a and the paper 2 in the other portion from the winding portion 32b, and the winding portion width regulating guides 31a and 31b and the sheet width regulating guide 32
a, 32b can prevent the paper 2 from being damaged by the force applied thereto, and the paper 2 having any width can be reliably pinched by the width regulating guides 30a, 30b. Positioning can be reliably performed at a predetermined position.

The paper 2 positioned in the width direction by the paper support unit 10 as described above receives the pulling force from the drive roller unit 14 and unwinds the winding section 2, thereby causing the dot impact printing unit 11 to apply the paper. Supplied. In the present embodiment, the center position in the width direction of the paper 2 is adjusted so as to match the center position in the longitudinal direction of the drive roller unit 14, and the dot impact printing unit 11 is adjusted to the center position in the longitudinal direction of the drive roller unit 14. Since they are arranged at the same position, the dot impact printing unit 11 performs printing at the center position in the width direction regardless of the width of the paper 2. Therefore, even if the dot impact print head unit 11 is not moved according to the width of the paper 2, the paper 2 hardly meanders due to the resistance applied to the paper 2 from the dot impact print head 12.

The paper 2 having the back side printed by the dot impact printing unit 11 is subsequently supplied to the drive roller unit 14. As described above, in the ink jet printer 1 of the present embodiment, the driving roller 5
The drive roller unit 14 having the pressure roller 6 is symmetrical with respect to the center position in the longitudinal direction, and the center position of the drive roller unit 14 in the longitudinal direction is regulated by the sheet support unit 10 so that the sheet 2 conveyed. At the center position in the width direction. Accordingly, in the drive roller unit 14, the drive roller 5 and the pressure roller 6 are symmetrically pressed against the sheet 2 at the center position in the width direction, and an equal force is applied to both sides of the center position in the width direction of the sheet 2. Is added.

As described above, in the present embodiment, the center position of the sheet 2 in the width direction is made the same regardless of the sheet width by the sheet supporting unit 10 and the driving roller 5
In addition, the arrangement of the pressure roller 6 is symmetrical in the longitudinal direction, and the center position in the width direction of the sheet 2 coincides with the center position in the longitudinal direction of the drive roller 5 and the pressure roller 6. For example, as shown in FIG.
In any case of A "," B ", and" C ", the drive roller 5 and the pressure roller 6 are arranged so as to be symmetrical with respect to the center position in the width direction of the paper 2. 2 hardly meanders at the time of conveyance due to the non-uniform force from the drive roller unit 14 regardless of its width.

In this embodiment, since the length of the pressure roller 6 is shorter than the length of the drive roller 5, when the paper 2 having a width larger than the length of the pressure roller 6 is used, 2 is only partially driven roller 5 and pressure roller 6
And can not be sandwiched. Therefore, in the width direction of the paper 2, the auxiliary guide 8 presses the paper 2 against the drive roller 5 in a portion where the pressure roller 6 does not exist. Therefore, even when the paper 2 having a width larger than the length in the longitudinal direction of the pressure roller 6 is used, the paper 2
Can be pressed against the drive roller 5 in the entire width direction, so that the meandering of the paper 2 is more effectively suppressed.

Next, the paper 2 conveyed to the ink jet printing unit 15 is printed by the ink jet head 16 reciprocating along the width direction of the paper 2 at a slight distance from the paper 2. . Then, the paper 2 on which printing has been completed is continuously conveyed to the cutting unit 17, and
After being cut to a predetermined length, it is discharged from the discharge port 28.

As described above, according to the present embodiment, by adjusting the winding portion width regulating guides 31a and 31b and the sheet width regulating guides 32a and 32b, the winding portion 2a and the winding portion 2a The center position of the unraveled paper 2 in the width direction can be the same regardless of the width of the paper 2. Further, the drive roller 5 and the pressure roller 6 are each symmetric with respect to the center position in the longitudinal direction, and
Since the center position in the longitudinal direction of the drive roller 5 and the pressure roller 6 is arranged so as to coincide with the center position in the width direction of the sheet 2, the center position in the width direction of the sheet 2 is independent of the width of the sheet 2. Since the drive roller 5 and the pressure roller 6 are evenly pressed against both of them, the print medium hardly meanders during transportation.

Further, in the present embodiment, since only one drive roller 5 and one pressure roller 6 can convey the paper 2 of all widths, the cost of the drive roller 5 and the pressure roller 6 can be reduced. And adjustment of each roller can be performed in one place. Furthermore, as in the case where a plurality of drive rollers 5 and pressure rollers 6 are used, uneven forces are applied to both sides of the center position in the width direction of the sheet 2 due to individual differences between the rollers due to manufacturing errors of the rollers. The paper 2 is not added, and the meandering of the paper 2 can be suppressed more effectively.

Further, in this embodiment, the dot impact print head 12 is arranged at a position corresponding to the center position of the paper 2 in the width direction. Printing can be performed on each sheet 2 in the same positional relationship without moving the dot impact print head 12 for each width. That is, the paper 2 hardly meanders due to the resistance applied to the paper 2 from the dot impact print head 12.

As described above, a preferred embodiment of the present invention has been described. However, the present invention is not limited to the above-described embodiment.
Various design changes can be made. For example, in the above-described embodiment, the positioning of the paper in the width direction is performed by the winding width control guide and the paper width restriction guide.
Although it is carried out at the winding part of the paper and the part unwound from the winding part, it may be positioned at any one of the above,
The print medium may be positioned at a portion other than the above.

In the above-described embodiment, the drive roller unit has only one drive roller and one pressure roller, but the drive roller unit has at least one symmetrical region in the longitudinal direction. If so, a plurality of drive rollers and pressure rollers may be provided.

Further, in the above embodiment, the case where the longitudinal center positions of the driving roller and the pressing roller coincide with each other has been described, but the center positions of the driving roller and the pressing roller in the longitudinal direction are not necessarily required. Need not match.

In the above-described embodiment, the pressure roller is supported by the support member that is rotatable about the fulcrum. However, the pressure roller may be any configuration as long as the paper can be pressed against the drive roller and conveyed. May be used.
Further, the auxiliary guide for pressing the sheet to the driving roller together with the pressing roller is not limited to the sheet metal member, but may be any as long as it has the same function.

In the above-described embodiment, the dot impact printing unit, the driving roller unit, the ink jet printing unit, and the cutting unit are arranged in this order in the paper transport direction. It suffices if it is on the upstream side in the paper transport direction, or it may not be provided. Further, the drive roller unit may be located at any position as long as it is on the upstream side in the paper transport direction of the cutting unit.

In the above-described embodiment, a long sheet wound in a roll is used as a print medium. However, a long sheet not wound in a roll may be used. . Further, a thin plastic or the like other than the paper may be used.

[0059]

As described above, according to the first aspect, the rollers included in the drive roller unit are symmetrically pressed against the print medium at the center position in the width direction,
An equal force is applied to both sides of the center position in the width direction of the print medium. Therefore, the printing medium hardly meanders during transportation.

According to the second aspect, it is possible to easily adjust the position of the roller in the driving roller unit, and it is possible to suppress the manufacturing cost of the driving roller unit. Also,
Uneven force is applied to both sides of the center position in the width direction of the print medium due to individual differences between the rollers due to manufacturing errors, such as when the print medium is sandwiched between three or more rollers in the drive roller unit. Since the print medium is not conveyed, the meandering of the print medium during transport can be more effectively suppressed.

According to the third aspect, even if the dot impact print head is not moved according to the width of the print medium, the print medium hardly meanders due to the resistance applied to the print medium from the dot impact print head. .

[Brief description of the drawings]

FIG. 1 is a diagram illustrating a schematic configuration of an ink jet printer according to an embodiment.

FIG. 2 is a perspective view illustrating a schematic configuration of a sheet supporting unit according to the exemplary embodiment.

FIG. 3 is a front view illustrating a schematic configuration of a sheet supporting unit illustrated in FIG. 2;

FIG. 4 is a diagram showing a schematic configuration of a drive roller unit of the ink jet printer according to the embodiment.

FIG. 5 is a diagram illustrating a schematic configuration of a driving roller unit of a conventional ink jet printer.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Ink-jet printer 2 Paper 2a Winding part 5 Drive roller 6 Pressure roller 8 Auxiliary guide 10 Paper support unit 11 Dot impact print unit 12 Dot impact print head 14 Drive roller unit 15 Inkjet print unit 16 Inkjet head 17 Cutting unit 20 Housing Reference Signs List 22 motor 25 controller 28 discharge port 30a, 30b width regulation guide 31a, 31b winding section width regulation guide 32a, 32b paper width regulation guide 33a, 33b arm 40 guide drive mechanism 42 screw shaft 44 transmission gear 45 transmission gear 47 arc-shaped member 48 Torque Keeper 50 Storage Container

Claims (3)

[Claims] 1. A printing unit for performing printing on a long printing medium by an ink-jet method, and the printing medium can be inserted between the printing unit and the printing unit to supply the printing medium to the printing unit. And a drive roller unit on which a plurality of rollers are arranged so as to have at least one region symmetrical with respect to the center position of the drive roller unit in the width direction of the print medium regardless of the width of the print medium. And a position regulating section for regulating the position in the width direction of the print medium so as to coincide with the center position of any of the regions. 2. The ink-jet printer according to claim 1, wherein the printing medium is sandwiched between the two driving rollers only by the two rollers arranged to face each other. 3. The dot impact print head according to claim 1, wherein a dot impact print head is arranged at a position corresponding to a center position in the width direction of the print medium regulated by the position regulating section. Ink jet printer.