JPH11139638A - Sheet guide, roll sheet setting shaft and printer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sheet guide, a roll sheet setting shaft and a printer using the sheet guide and the roll sheet setting shaft with members for centering which do not interfere with roll sheet setting, small and capable of highly precisely centering and easily carrying out centering work. SOLUTION: This sheet guide is constituted by furnishing a shaft one end of which is fixed on a bas plate and to regulate a position in the cross direction of a sheet to be carried on the shaft. In this case, the shaft is constituted of a spiral shaft 12 free to rotate and constituted by providing spiral grooves the spiral directions of which are opposite directions to each other from roughly central positions in the axial direction and a cylindrical shaft 13 to store the spiral shaft 12, forming opening pats 13d, 13e extending in the axial direction at specified positions on an outer periphery and one end of which is fixed on the base plate 11. Additionally, pins 21, 22 on central parts of which holes through which the cylindrical shaft 13 passes are formed and through the opening parts 13d and 13e of the cylindrical shaft 13, the pin 21 and 22 are engaged with the spiral groove of the spiral shaft 12 are furnished. A pair of guide plates 17, 18 to approach and separate to and from each other along the cylindrical shaft through projected parts to be engaged with the spiral groove by rotation of the spiral shaft 12 is furnished.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention comprises a paper guide for guiding a paper fed from a roll paper used in a printer or the like, a roll paper setting shaft for setting the roll paper, and a paper guide or a roll paper setting shaft. It concerns a printer.

[0002]

2. Description of the Related Art In a printer using roll paper as described above, it is preferable that the center line in the width direction of the paper and the printing unit coincide with each other so that printing can be performed uniformly left and right across the center line of the paper. In particular, when using a thermal printer for the printing section, the paper is pressed by pressing the back of the print head with a spring, so if the center line of the print head and the center line of the paper are misaligned, And the print densities are non-uniform on the left and right.

Conventionally, a technique for matching the center line of the print head with the center line of the paper is disclosed in Japanese Patent Application Laid-Open No. 62-8395.
No. 8 discloses a technique disclosed in Japanese Patent Publication No. In this technique, a holding member for holding both ends of a roll paper is supported by an external X-shaped lever, and an intersection of the levers is supported on a printer main body with a pin, and if one of the holding members is moved, the other can move in the opposite direction and be centered. It is configured as follows.

[0004]

However, the above-mentioned technique has a problem that it is difficult to reduce the size of the X-shaped lever and it is an obstacle. Therefore, a method of manually centering each member in contact with both ends of the roll paper without moving them in accordance with the scale is also performed, but there is a problem in workability and centering accuracy. The latter method is also used as a paper guide for a printer that handles continuous paper, but has the same problem as described above.

SUMMARY OF THE INVENTION The present invention has been made in view of the above points, and a member for centering does not hinder a roll paper set, and is small in size, has good centering accuracy, and can easily perform centering work. An object of the present invention is to provide a printer using the set shaft, the paper guide, and the roll paper set shaft.

[0006]

According to a first aspect of the present invention, there is provided a shaft having one end fixed to a base plate, and the position of a sheet conveyed on the shaft in the width direction is determined. In the paper guide to be regulated, the shaft is rotatable, and a helical shaft provided with helical grooves whose helical directions are opposite to each other from about the central position in the axial direction, and the helical shaft is housed in a predetermined position on the outer periphery. An opening extending in the axial direction is formed at one end, and one end is formed of a cylindrical shaft fixed to the base plate, a hole is formed at the center of the cylindrical shaft, and a helical shaft is formed through the opening of the cylindrical shaft. And a pair of guide plates approaching and separating from each other along the cylindrical axis through the projection engaging with the spiral groove by rotation of the spiral shaft. And

According to a second aspect of the present invention, there is provided a roll paper setting shaft for inserting a shaft having one end fixed to a base plate into a center hole of the roll paper to regulate a position in a width direction of the roll paper. The shaft is rotatable, and a helical shaft provided with helical grooves whose helical directions are opposite to each other from a central position in the axial direction, and an opening that accommodates the helical shaft and extends axially at a predetermined position on the outer periphery. And a cylindrical shaft fixed at one end to the base plate. A hole is formed in the center of the cylindrical shaft so that the cylindrical shaft penetrates and engages the spiral groove of the spiral shaft through the opening of the cylindrical shaft. A projection is provided, and a pair of pressing members approaching and separating from each other along the cylindrical axis via the projection engaging with the spiral groove by rotation of the spiral shaft are provided.

[0008] Further, the invention described in claim 3 is based on claim 2.
In the roll paper setting shaft described in the above, the pressing member on the opposite side to the base plate side has a protrusion engaged with the spiral groove of the spiral shaft, and is a movable member movable in the axial direction, and is detachable from the movable member. And a free holding plate.

The invention described in claim 4 is the first invention.
In a printer including the paper guide described in (1).

According to a fifth aspect of the present invention, there is provided a printer including the roll paper setting shaft according to the second or third aspect.

[0011]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a view showing the structure of a paper guide according to the first aspect of the present invention. In FIG.
Reference numeral 11 denotes a base plate of a printer to which the paper guide 10 is attached. The paper guide 10 has a spiral shaft 12 and the spiral shaft 1.
2 is provided with a cylindrical shaft 13, and one end of the cylindrical shaft 13 is fixed to the base plate 11. The helical shaft 12 is a helical shaft provided with helical grooves whose helical directions are opposite to each other from about the central position in the axial direction, and two grooves for each helical direction. It is rotatably arranged in the shaft 13.

A rotation guide groove 15 is provided substantially at the center of the spiral shaft 12.
The tip of a pin 16 fixed to the center of the cylindrical shaft 13 is engaged in the rotation guide groove 15. Reference numeral 14 denotes an operation knob fixed to the other end of the helical shaft. By rotating the operation knob 14, the helical shaft 12 is rotated by the rotation guide groove 15 being guided by a pin 16.

Reference numeral 17 denotes a guide plate on the base plate 11 side, and reference numeral 18 denotes a guide plate on the operation knob 14 side. Guide plates 17 and 18
Each has a hole with a diameter through which the cylindrical shaft 13 penetrates at the center thereof. As will be described in detail later, the guide plates 17 and 18 project from the inner wall surface of the hole to openings 13d and 13e provided in the outer peripheral portion of the cylindrical shaft 13, and the tip ends of the guide plates 17 and 18 have the spiral shape of the spiral shaft 12. Pin (projection) that engages with groove
21 and 22 are provided.

In the paper guide 10 having the above structure, when the operation knob 14 is rotated and the helical shaft 12 is rotated, the guide plates 17 and 18 are moved through the pins 21 and 22 which are engaged with the helical grooves according to the rotation direction. They move so as to approach or separate from each other along the cylindrical shaft 13. Therefore, the operation knob 14 is rotated according to the width of the sheet W conveyed between the pair of guide plates 17 and 18, and the guide plate 17 is rotated.
And 18 can be easily or accurately centered on the paper W by moving them closer to or away from each other. Hereinafter, the configuration of each component of the paper guide will be described.

The helical shaft 12 includes a helical shaft member 12-1 on the base plate 11 side of the printer and a helical shaft member 12 on the operation knob 14 side.
-2. FIG. 2 shows the base plate 1 of the printer.
1A is a front view, FIG. 1B is a left side view, and FIG. 1C is a right side view. 3A and 3B show the structure of the spiral shaft member 12-2 on the operation knob 14 side. FIG. 3A is a front view, FIG. 3B is a left side view, and FIG. 3C is a right side view. is there.

As shown in FIG. 2, the helical shaft member 12-1 on the side of the base plate 11 has a hole 12-1d having a predetermined size formed in the center portion at one end in an axial direction from one end, and is formed in the axial direction from the one end. Spiral grooves 12-1a and 12-1a 'having predetermined dimensions are formed, and a small-diameter portion 12-1e having predetermined dimensions is formed in the axial direction from the end of the spiral grooves 12-1a and 12-1a'. At the end of 12-1e, two large diameter flanges 12-1b and 12-1c for forming the rotation guide groove 15 are formed, and at the other end, a small diameter projection 12-1f is formed. ing.

The helical shaft member 12-2 on the operation knob 14 side has a small-diameter portion 12-2b having a predetermined dimension formed in the axial direction from one end, and a helical groove 12-2 extending from the end of the small-diameter portion 12-2b to the other end.
-2a and 12-1a 'are formed, and a hole 12-2c of a predetermined size is formed in the center from one end to the other in the axial direction. The inside diameter of the hole 12-2c is large enough to fit the protrusion 12-1f at the other end of the spiral shaft member 12-1. The other end surface of the spiral shaft member 12-1 is provided with a pair of fitting projections 12-2d that fit into holes of the operation knob 14.

The helical shaft 12 has a protrusion 12-1f at the other end of the helical shaft member 12-1 and the helical shaft member 12-2 has a hole 12 at one end.
-2c, and the small-diameter portion 12-2 of the spiral shaft member 12-2
b of the pin hole 12-2e and the protrusion 1 of the spiral shaft member 12-1
The helical shaft member 12-1 and the helical shaft member 12-2 are connected by fitting a pin into the 2-1f pin hole 12-1g. Thereby, the spiral directions of the spiral grooves 12-1a and 12-1a 'of the spiral shaft member 12-1 and the spiral grooves 12-2a and 12-2a' of the spiral shaft member 12-2 are opposite to each other.

FIGS. 4A and 4B show the structure of the cylindrical shaft 13. FIG. 4A is a front view, FIG. 4B is a left side view, and FIG. It is A sectional drawing. The cylindrical shaft 13 is formed of a cylindrical member having an inner diameter capable of housing the spiral shaft 12,
One end is closed by a closing portion 13a and the other end is opened. A helical shaft support projection 13b that is inserted into a hole 12-1d of a helical shaft member 12-1 that forms the helical shaft 12 is formed on the inner surface of the closed portion 13a at one end. A screw hole 13c for fixing one end of the cylindrical shaft 13 to the base plate 11 is formed in the closing portion 13a.

Openings 13d and 13e extending in the axial direction are formed at predetermined positions on the outer periphery of the cylindrical shaft 13.
The openings 13d and 13e are respectively formed by the spiral shaft members 12-
1 spiral groove 12-1a, 12-1a 'and spiral shaft member 1
2-2 spiral grooves 12-2a and 12-2a 'and have dimensions substantially equal to each other. A pair of holes 13f into which a pin 16 whose tip is engaged with the rotation guide groove 15 of the helical shaft 12 is provided on the outer periphery of the central portion of the cylindrical shaft 13.

FIGS. 5A and 5B show the structure of the guide plate 17, wherein FIG. 5A is a front view and FIG. 5B is a left side view. Since the guide plate 18 has substantially the same structure as the guide plate 17, its description is omitted. The guide plate 17 has a hole 17a in the center thereof through which the cylindrical shaft 13 passes, and a flange 1 having a guide surface 17c for guiding the edge of the paper W at one end thereof.
7b is formed, and the other end is a small diameter portion 17d.
Holes 17e are formed at predetermined positions of the small-diameter portion 17d, in which holes 21e into which the pins 21 whose front ends are respectively engaged with the spiral grooves 12-1a and 12-1a 'of the spiral shaft member 12-1 are fitted. . Therefore, the guide plate 17 can be smoothly moved according to the rotation of the spiral shaft 12.

FIG. 6 shows the structure of the operation knob 14.
FIG. 1A is a partial sectional front view, and FIG. 1B is a left side view. The operation knob 14 has a disk shape as shown in the figure, and has a helical shaft member 12-2 which constitutes the helical shaft 12 on one side.
Is formed with a pair of fitting holes 14a for fitting the fitting projections 12-2d at the other end thereof, and guide plates 17 and 18 on the other side surface.
Are provided with arrows 14b and the like indicating the rotation directions approaching each other.

First, assembling the paper guide having the above structure,
One end of the cylindrical shaft 13 is fixed to the base plate 11 of the printer with screws 23. Next, the spiral shaft support protrusion 13b of the closing portion 13a
The spiral shaft 12 is housed in the cylindrical shaft 13 so as to be inserted into the hole 12-1d at one end of the spiral shaft member 12-1. Subsequently, the pin 16 is fitted into the pair of holes 13 f of the cylindrical shaft 13, and the tip thereof is engaged with the rotation guide groove 15 of the spiral shaft 12.
Next, the cylindrical shaft 13 is inserted into a hole provided at the center of each of the guide plates 17 and 18, and the tip of the cylindrical shaft 13 is
-1 of the spiral grooves 12-1a, 12-1a 'and the spiral grooves 12-2a, 12-2a' of the spiral shaft member 12-2 are fitted into the guide plate 17, the guide plate 17, and the guide. Attach plate 18. Thereafter, the operation knob 14 is fitted by fitting the fitting projection 12-2d of the spiral shaft member 12-2 constituting the spiral shaft 12 into the fitting hole 14a.

With the above-described structure of the paper guide,
The centering mechanism that adjusts the distance between the pair of guide plates 17 and the guide plates 18 toward and away from each other in the axial direction to match the width of the paper W is housed in the cylindrical shaft 13, so that the centering mechanism does not interfere with operations or the like. Therefore, the centering operation is easy and the centering can be performed with high accuracy. Rather than directly moving the guide plates 17 and 18 to adjust the position, the rotation of the spiral shaft 12 causes the pins 21 and 22 to engage with the spiral grooves to approach and separate from each other along the cylindrical shaft 13. Due to the configuration, the reaction force is large against the force of the guide plates 17 and the guides 18 to be shifted in the axial direction, and the guide plates 17 and the guide positions 18 are not easily shifted from the set positions.

7 and 8 are views showing the structure of the roll paper setting shaft according to the second aspect of the present invention. FIG. 7 is a longitudinal sectional view, and FIG. 8 is an engagement state between the moving member 33 and the pressing plate 32. FIG. In FIGS. 7 and 8, portions denoted by the same reference numerals as those in FIGS. 1 to 6 indicate the same or corresponding portions. Reference numeral 11 denotes a base plate of a printer on which the roll paper setting shaft 30 is mounted. The roll paper setting shaft 30 includes a spiral shaft 12 and a cylindrical shaft 13 in which the spiral shaft 12 is housed.
One end of 3 is fixed to the base plate 11 with screws 23, 23. Further, the helical shaft 12 is a helical shaft provided with helical grooves 12-1a, 12-1a 'and 12-2a, 12-2a' whose helical directions are opposite to each other from an approximately central position in the axial direction.
It is rotatably arranged in the cylindrical shaft 13.

A rotation guide groove 15 is provided substantially at the center of the spiral shaft 12.
The tip of a pin 16 fixed to the center of the cylindrical shaft 13 is engaged with the rotation guide groove 15. By rotating the operation knob 14 fixed to the other end of the spiral shaft 12, the spiral shaft 12 is rotated by the rotation guide groove 15 being guided by the pin 16.

Reference numeral 31 denotes a holding plate on the base plate 11 side, and 32 denotes a holding plate on the operation knob 14 side. The holding plate 31 has a central hole formed with a hole through which the cylindrical shaft 13 penetrates, and the holding plate 31 is provided from the inner wall surface of the hole to the outer peripheral portion of the cylindrical shaft 13 as described later in detail. A pin (projection) 21 is provided which protrudes into the opening 13 d and whose leading end engages with the spiral grooves 12-1 a and 12-1 a ′ of the spiral shaft 12. As described later in detail, the holding plate 32 is engaged with the outer peripheral portion of the moving member 33 and moves in conjunction with the movement of the moving member 33 in the axial direction. The moving member 33 is formed with a hole having a diameter through which the cylindrical shaft 13 penetrates in the center, similarly to the guide plate 18, and an opening formed in the outer peripheral portion of the cylindrical shaft 13 from the inner wall surface of the hole. Pins (protrusions) 22 are provided at the front and rear of the helical shaft 12 so as to protrude into the helical grooves 12-2a and 12-2a 'of the helical shaft 12.

In the roll paper setting shaft 30 having the above structure, when the operation knob 14 is rotated and the helical shaft 12 is rotated, the helical grooves 12-1a and 12-1 depend on the direction of rotation.
The holding plate 31 and the holding plate 32 smoothly move toward and away from each other along the cylindrical shaft 13 via the pins 21 and 22 that engage with a ′ and 12-2a and 12-2a ′. . Therefore, the pair of holding plates 31 and 32
By rotating the operation knob 14 depending on the width dimension of the roll paper set between them, the centering of the roll paper, in which the pressing plates 31 and 32 approach or separate from each other, is easy,
And it can be performed with high accuracy. Hereinafter, the configuration of each component of the paper guide will be described.

The structure of the spiral shaft 12 is the same as that of the paper guide shown in FIGS.
The operation knob 14 is the same as that of the paper guide shown in FIG.

FIGS. 9A and 9B are views showing the structure of the holding plate 31. FIG. 9A is a longitudinal sectional view, and FIG. 9B is a right side view. The holding plate 31 has a rectangular shape having both ends in an arc shape, a hole 31a through which the cylindrical shaft 13 penetrates is formed at the center thereof, and four ribs 31b with which the end surface of the roll paper abuts are formed on one surface thereof. A small-diameter portion 3 having a predetermined thickness is provided on the outer peripheral portion of the hole 31a on the opposite surface.
1c is formed at a predetermined position of the small-diameter portion 31c, and the tip ends of the spiral grooves 12-1a and 12-1 of the spiral shaft member 12-1 are formed.
Two holes 31d into which the pins 21 to be engaged with a ′ are fitted are formed symmetrically.

FIGS. 10A and 10B show the structure of the moving member 33. FIG. 10A is a front view, FIG. 10B is a right side view, and FIG. 10C is a plan view. The moving member 33 is disc-shaped, has a hole 33a formed at the center thereof, through which the cylindrical shaft 13 penetrates, and a flange 33c having an abutting surface 33b with which the end surface of the roll paper abuts at one end. Presser plate 32 at the end
A pair of projections 33d, 33d are provided on the upper and lower sides in total, and a pair of engagement projections 33d, 33d is fitted with an engagement pin of a holding plate 32 described later in detail. A mating groove 33e is formed, and a groove 33f is formed between the flange portion 33c and the protrusion 33d so that the guide piece of the holding plate 32 is engaged. The tip of the spiral member 12-2 of the spiral shaft member 12-2 is located at a predetermined position of the moving member 33.
a, hole 3 into which pin 22 engaging with 12-2a 'is fitted
3 g are symmetrically formed.

FIGS. 11A and 11B show the structure of the holding plate 32. FIG. 11A is a front sectional view (A-A section of FIG. 11B), FIG. 11B is a left side view, and FIG. (C) is BB in FIG.
It is sectional drawing. The holding plate 32 has a rectangular shape with both ends in an arc shape, and a hole 32a in the center thereof for receiving the moving member 33.
Are formed, and a pair of engaging pins 32b, 32b are formed on the inner surface of the hole 32a so as to face each other.
A pair of guide pieces 32c, 32c are provided on both sides of b with a predetermined gap. Also, presser plate 3
4 are provided with four ribs 3 on which the end face of the roll paper abuts.
2d is formed.

In assembling the roll paper setting shaft having the above structure, first, one end of the cylindrical shaft 13 is fixed to the base plate 11 of the printer with screws 23. Next, the spiral shaft supporting projection 13b of the closing portion 13a is inserted into the hole 12-1d at one end of the spiral shaft member 12-1.
The spiral shaft 12 is housed in the cylindrical shaft 13 so as to be inserted into the cylindrical shaft 13. Subsequently, the pin 16 is fitted into the pair of holes 13 f of the cylindrical shaft 13, and the tip thereof is engaged with the rotation guide groove 15 of the spiral shaft 12. Next, the cylindrical shaft 13 is inserted into the hole 31a provided in the center of the holding plate 31, and the tip of which is engaged with the spiral grooves 12-1a and 12-1a 'of the spiral shaft member 12-1. 21 are fitted respectively, and the holding plate 31 is attached.

Next, the cylindrical shaft 13 is inserted into the hole 33a provided in the center of the moving member 33, and the tip is engaged with the spiral grooves 12-2a and 12-2a 'of the spiral shaft member 12-2. The moving members 33 are attached by fitting the corresponding pins 22 respectively. Subsequently, the protrusion 33 on the outer periphery of the moving member 33
The engaging pin 32b of the hole 32a of the holding plate 32
Then, the outer periphery of the moving member 33 is inserted into the hole 32a, and then the engaging pin 32b of the holding plate 32 and the guide piece 32c are inserted into the groove 3 of the moving member 33.
3f, the engaging pins 32b, 32b
The holding plate 32 is rotated until it engages with 3e, and the holding plate 32 is attached to the moving member. Thereafter, the operation knob 14 is fitted by fitting the fitting projection 12-2d of the spiral shaft member 12-2 of the spiral shaft 12 into the fitting hole 14a.

With the roll paper setting shaft 30 having the above-described structure, the centering mechanism for adjusting the distance between the pair of pressing plates 31 and 32 toward and away from each other in the axial direction to adjust the width of the roll paper is a cylindrical shaft. Since it is housed in the housing 13, the centering operation can be performed easily and accurately with no hindrance in operation or the like. Rather than directly moving the holding plate 31 and the holding plate 32 to adjust the position, the rotation of the spiral shaft 12 causes the pins 21 and 22 to engage with the spiral groove to approach and separate from each other along the cylindrical shaft 13. Because of the configuration, the holding plate 31
In addition, there is a large reaction force against the force of the holding plate 32 that tends to shift in the axial direction, and the positions of the holding plate 31 and the holding plate 32 do not easily shift from the set positions.

In the roll paper setting shaft 30, the holding plate 32 is attached to the outer periphery of the moving member 33.
Instead of this, a member that can be brought into contact with the end face of the roll paper in a state where it can be inverted and stand upright on the outer periphery of the moving member, or a member that can come into contact with the end face of the roll paper in a state where it can come out and retract is provided It may be a holding plate.

Further, the cross-sectional shape of the cylindrical shaft 13 is not limited to a circle, but may be any shape such as an ellipse, for example, as long as the conveyed paper or the set roll paper inner diameter is slippery. Also,
The rotation operation of the helical shaft 12 is not limited to the operation by the operation knob 14, and a hole into which the hexagon wrench is fitted may be provided at the other end, and the hex wrench may be fitted into the hole to rotate. . Further, the roll set shaft and the paper guide shaft may be simultaneously adjusted by driving the motor according to the setting data from the printer body.

In the paper guide shown in FIG. 1, a moving member having a structure shown in FIG. 10 may be used for the guide plates 17 and 18.

FIG. 12 is a view showing a schematic configuration example of a printer on which the paper guide 10 and the roll paper setting shaft 30 are mounted. As shown in the figure, the paper guide 10 and the roll paper setting shaft 30 are attached to the base plate 11 of the printer.
Reference numeral 40 denotes a printing unit including a print head 41 and a platen 42,
43 is a winding shaft, and 44 is a lever. The centering of the paper guide 10 and the roll paper setting shaft 30 is aligned with the center of the printing unit 40. In the printer having the above structure, the print head 41 is raised by turning the lever 44 so that the paper guide 10 and the roll paper setting shaft 30 are widened to the maximum width, and the roll paper RW is set on the roll paper setting shaft 30. Thereafter, the operation knob 14 is rotated (for example, CLO
(In the direction of SE), and the centering is performed.

The roll paper RW is formed by winding a paper W on which labels are continuously attached, and the paper W fed from the roll paper RW is guided by the paper guide 10 and guided to the printing unit 40. In the printing unit 40, the label is printed by the print head 41, and the label is peeled from the descending paper W in a state where the paper W is bent at the tip of the platen 42 at an acute angle. It is wound up.

The printer using the paper guide and the roll paper setting shaft according to the present invention is not limited to a label printer, but requires a centering of paper, such as a cassette printer cassette, a facsimile machine, a copier, and the like. It can be widely used for items that require centering of roll paper.

[0042]

As described above, according to the present invention, the following excellent effects can be obtained.

(1) According to the invention described in each of the claims, the centering mechanism for adjusting the interval between the pair of guide plates or the pair of pressing plates toward and away from each other in the axial direction to adjust the width of the paper or the width of the roll paper, Since it is housed in the cylindrical shaft, it does not hinder the operation or the like, and the centering operation is easy and accurate centering can be performed. Also, since the position is not adjusted by directly operating the guide plate or the holding plate, but is configured to approach and separate from each other along the cylindrical axis via the protrusion engaging with the spiral groove by rotation of the spiral shaft, The reaction force is large against the force of the guide plate or the holding plate that tends to shift in the axial direction, and the position of the guide plate or the holding plate does not easily shift from the set position.

(2) According to the second aspect of the present invention, since the centering mechanism enters the inner diameter hole of the roll paper,
There is no need to provide a special space for arranging the centering mechanism, and space can be saved.

(3) According to the third aspect of the present invention, since the pressing member on the opposite side of the base plate is detachable from the moving member, the pressing member is larger than the inner diameter of the roll paper. By doing so, the end surface of the roll paper can be reliably pressed.

(4) According to the invention described in claim 4 or 5, since the centering mechanism is downsized, the printer can be downsized.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing the structure of a paper guide according to the first embodiment of the present invention.

2A and 2B are diagrams showing the structure of a spiral shaft member of a spiral shaft, wherein FIG. 2A is a front view, FIG. 2B is a left side view, and FIG. 2C is a right side view.

3 (a) is a front view, FIG. 3 (b) is a left side view, and FIG. 3 (c) is a right side view.

4 (a) is a front view, FIG. 4 (b) is a left side view, and FIG. 4 (c) is a sectional view taken along line AA of FIG. 4 (b). It is.

5A and 5B are diagrams showing a structure of a guide plate, wherein FIG. 5A is a front view and FIG. 5B is a left side view.

6A and 6B are diagrams showing the structure of an operation knob, wherein FIG. 6A is a partial cross-sectional front view, and FIG. 6B is a left side view.

FIG. 7 is a longitudinal sectional view showing a structure of a roll paper setting shaft according to the second aspect of the invention.

FIG. 8 is a diagram showing an engagement state between a moving member and a holding plate.

9A and 9B are diagrams showing the structure of the holding plate, wherein FIG. 9A is a longitudinal sectional view and FIG. 9B is a right side view.

10A and 10B are diagrams showing a structure of a moving member, wherein FIG. 10A is a front view, FIG. 10B is a right side view, and FIG. 10C is a plan view.

11A and 11B are diagrams showing the structure of a holding plate, wherein FIG. 11A is a longitudinal sectional view, FIG. 11B is a left side view, and FIG. 11C is FIG.
FIG.

FIG. 12 is a diagram illustrating a schematic configuration example of a printer.

[Explanation of symbols]

 REFERENCE SIGNS LIST 10 paper guide 11 printer base plate 12 helical shaft 12-1 helical shaft member 12-2 helical shaft member 13 tubular shaft 14 operation knob 15 rotation guide groove 16 pin 17 guide plate 18 guide plate 21 pin 22 pin 30 roll paper set Shaft 31 Holding plate 32 Holding plate 33 Moving member

Claims (5)

[Claims] 1. A paper guide, comprising a shaft having one end fixed to a base plate, for regulating a position of a sheet conveyed on the shaft in a width direction, wherein the shaft is rotatable and approximately at the center in the axial direction. A helical shaft provided with helical grooves whose helical directions are opposite to each other from the position,
An opening extending in the axial direction is formed at a predetermined position on the outer periphery for accommodating the spiral shaft, and one end includes a cylindrical shaft fixed to the base plate, and a hole through which the cylindrical shaft penetrates is formed at the center. A projection that engages with the spiral groove of the helical shaft through the opening of the cylindrical shaft, and that the projection is engaged with the spiral groove by the rotation of the helical shaft. A paper guide comprising a pair of guide plates approaching and leaving along. 2. A roll paper set shaft for inserting a shaft, one end of which is fixed to a base plate, into a center hole of the roll paper to regulate a position of the roll paper in a width direction, wherein the shaft is rotatable and axially movable. A helical shaft provided with helical grooves in which the helical directions are opposite to each other from about the center position,
An opening extending in the axial direction is formed at a predetermined position on the outer periphery for accommodating the spiral shaft, and one end includes a cylindrical shaft fixed to the base plate, and a hole through which the cylindrical shaft penetrates is formed at the center. A projection that engages with the spiral groove of the helical shaft through the opening of the cylindrical shaft, and that the projection is engaged with the spiral groove by the rotation of the helical shaft. A roll paper setting shaft comprising a pair of pressing members which approach and separate along the roll paper setting shaft. 3. A holding member on the opposite side of the base plate side has a protrusion engaged with a spiral groove of the spiral shaft, and is a movable member movable in the axial direction, and is detachable from the movable member. The roll paper setting shaft according to claim 2, further comprising a presser plate. 4. A printer comprising the paper guide according to claim 1. 5. A printer comprising the roll paper setting shaft according to claim 2 or 3.