JP3137556B2 - Printer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a printer for printing on continuous paper, and more particularly to a paper feed mechanism.

[0002]

2. Description of the Related Art Conventionally, there is a printer which performs printing on continuous paper, which further transports continuous paper transported by a pin tractor from a printing unit to a paper discharge mechanism. The printing section of such a printer includes a print head and a platen opposed thereto, and the continuous paper is sandwiched between the print head and the platen while being guided by a pin wheel from a pin tractor.

A roller-shaped pin wheel is rotated by a shaft having a square cross section, and a plurality of pins are provided on the surface thereof at the same intervals as the pins of a pin tractor. At first, the pins of the pin tractor are inserted into the holes of the continuous paper, but as the pin tractor is driven and the continuous paper is conveyed, the pins come off one by one from the holes. Next, the pin of the pin tractor is inserted into the hole where the pin of the pin tractor is removed, and the continuous paper is further conveyed by rotating the pin wheel. In other words, the pin tractor and the pin wheel are separated from the pin
It is driven and rotated while always keeping the distance between the pins of the pin wheel inserted into the holes and the distance between the holes of the continuous paper.

[0004] The continuous paper printed by the printing unit is transported to a paper discharge mechanism. The paper discharge mechanism includes a feed roller that is driven to rotate and an upper roller that faces the feed roller. Continuous paper is conveyed while being sandwiched between the feed roller and the upper roller. The rotation speed of the feed roller is set slightly higher than the speed of feeding the continuous paper by the pin tractor. In this way, by increasing the transport force of the paper discharge mechanism than the transport force of the pin tractor,
A tension is applied to the continuous paper so that the pin of the pinwheel is normally inserted into the hole of the continuous paper so that stable conveyance is maintained.

[0005]

In the conventional printer, since the transport force of the paper discharge mechanism is made larger than the transport force of the pin tractor, the continuous paper is strongly pulled in the direction of the paper discharge mechanism. Also, since there is a slight gap in the molding between the pin wheel and its square shaft,
Only the pinwheel pulled by the continuous paper rotates more than the shaft by the gap, and the distance between the pin of the pin tractor that comes out of the hole of the continuous paper and the pin of the pinwheel inserted into the hole is preset. If the spread exceeds the predetermined value, the pin of the pin tractor and the pin of the pin wheel are fixed and their positions do not shift. There has been a problem that the sheet breaks and spreads, and furthermore, a line feed printing position shifts.

[0006]

In order to solve the above-mentioned problems, in a printer according to the present invention, a continuous paper transport mechanism located downstream of a printing unit is arranged with a pressing member and a pressing member separated from the pressing member. And a conveyance roller having a portion having a strong conveyance force and a portion having a weak conveyance force with respect to the continuous paper, and rotating with the pressing member sandwiching the continuous paper to change the conveyance force of the continuous paper. .

[0007]

The continuous paper is transported to the transport mechanism of the printer constructed as described above, the continuous paper is sandwiched between the pressing member and the transport roller, and a portion of the transport roller where the transport force is large due to the rotation of the transport roller. When the continuous paper faces the continuous paper, the continuous paper is held in a state of being bent by the transport roller and the pressing member. At this time, a relatively large transport force according to the rigidity of the continuous paper is obtained, and a portion where the transport force of the transport roller is small is obtained. Is relatively small in the state of facing the continuous paper.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described with reference to the drawings. Elements common to the drawings are denoted by the same reference numerals. FIG. 1 is a side view showing a first embodiment of the present invention, and FIG. 2 is a perspective view showing a printer of the first embodiment. In FIG. 2, the printer 1 has a transport mechanism 2 for transporting sprocket paper, which is continuous paper. A print head 3 and a platen 4 are provided on the inside front side. The paper discharge unit 25 is attached to an upper part of the platen 4.

In FIG. 1, a platen 4 includes a shaft 5
To be rotatable. The pulley 6 mounted coaxially has a belt 7 indicated by a dashed line.
Is wound between the shaft 9 of the stepping motor 8 and the shaft 9. The stepping motor 8 is rotationally driven by a control unit (not shown) according to the print data, and rotates the platen 4 in the direction of arrow A via the belt 7 and the pulley 6. The transport mechanism 2 of the printer 1 includes two rear tractor assemblies 10 and 11 provided at both ends of a transport path, a tractor belt 12 bridged between them, and a pin wheel 13 provided below the platen 4. It consists of.

The rear tractor assemblies 10, 11 are
They are attached to the housing so as to be rotatable by shafts 14 and 15, respectively. On the tractor belt 12, at equal intervals with sprocket holes provided at both ends of the sprocket paper 22,
The pin 16 is fixed. The pin wheel 13 is rotatably attached to the housing by a square shaft 17. The pin wheel 13 is connected to the platen 4 and the rear tractor assembly 11 by a gear (not shown). As a result, the platen 4 is
, The pin wheel 13 rotates in the direction of the arrow A and the rear tractor assembly 11 also rotates in the direction of the arrow A in synchronism therewith. When the rear tractor assembly 11 rotates in the direction of arrow A, the rear tractor assembly 10 rotates in the direction of arrow A and the tractor belt 12 rotates in the direction of arrow B.

Pins 20 are also fixed to the surface of the pin wheel 13 at regular intervals with the sprocket holes of the sprocket paper 22. The sprocket paper 22 has the pin 16 of the tractor belt 12 and the pinwheel 13 in the sprocket holes.
Of the print head 3 and the platen 4 are guided. When printing is performed, the stepping motor 8 is driven for each line feed according to the print data, and the shaft 9 rotates in the direction of arrow A by the line feed. As a result, the belt 7, the pulley 6, and the platen 4 rotate in the direction of arrow A, and the line feed of the sprocket sheet 22 sandwiched between the platen 4 and the print head 3 is performed. Further, the rotation of the platen 4 causes the pin wheel 13 and the tractor belt 12 to rotate by the same amount, and conveys the sprocket paper 22.

Here, the pins 16 of the tractor belt 12 are inserted into the sprocket holes of the sprocket paper 22 at first, but as the line feed is performed and the sprocket paper is conveyed, the pins 16 come out of the holes. It comes off one by one. Next, the pin 20 of the pin wheel 13 is inserted into the hole of the tractor belt 12 from which the pin 16 has come off, and the sprocket paper 22 is further conveyed by the rotation of the pin wheel 13. In other words, the distance between the pin 16 of the tractor belt 12 that comes out of the hole of the sprocket paper and the pin 20 of the pin wheel 13 inserted into the hole is always the distance between the hole of the sprocket paper 22 and the pinwheel 13. It is rotating while keeping the same.

The printed sprocket paper 22
Is discharged to the outside of the printer 1 by the paper discharge mechanism 21. The paper discharge mechanism 21 is composed of a feed roller 23 that is separate from the platen 4 as a driving source, and an upper roller 24. The feed roller 23 is rotated in the direction of arrow A by a shaft 26 attached to the side of the sheet discharge unit 25. The upper roller 25 rotates in a direction indicated by an arrow A ′ by a shaft 27 attached to a casing (not shown) of the printer 1.

The sprocket paper 22 is discharged between the feed roller 23 and the upper roller 24 to the outside of the printer 1. Here, the rotation speeds of the feed roller 23 and the upper roller 24 are set slightly higher than the speed at which the stepping motor 8 conveys the sprocket paper 22. Thus, the paper discharge mechanism 2 is less than the transport force of the tractor belt 12, the pin wheel 13, and the platen 4.
By increasing the transfer force of the tractor belt 12, the sprocket paper 22 is given a tension so that the tractor belt 12
The pin 20 of the pin wheel 13 is
Is inserted normally.

The paper discharging operation by the paper discharging mechanism 21 as described above will be described. 3 and 5 are side views showing the sheet discharging mechanism of the first embodiment, FIG. 4 is a top view seen from the direction of arrow C in FIG. 3, and FIG. 6 is a top view seen from the direction of arrow C in FIG. . In FIG. 3, the upper roller 24 has a substantially triangular shape with three convex portions 28 and three concave portions 29 formed on the surface thereof. Also, as shown in FIG.
The feed roller 23 and the upper roller 24 are provided separately from the shafts 26 and 27 attached in parallel with each other without contact. The sprocket paper 22 is sandwiched between the feed roller 23 and the upper roller 24, and is conveyed by rotating the feed roller 23 in the direction of arrow A and the upper roller 24 in the direction of arrow A '.

When the sprocket paper 22 is transported, the upper roller 24 rotates in the direction of arrow A ',
The convex portions 28 and the concave portions 29 alternately come to positions facing the feed roller 23. As shown in FIG. 3, when the convex portion 28 faces the feed roller 23, the upper roller 24
Presses the sprocket paper 22 toward the feed roller 23. That is, as shown in FIG. 4, the sprocket paper 22 is pressed and bent, and the sprocket paper 22 is strongly pulled in the direction of arrow D in FIG. As shown in FIG. 5, when the concave portion 29 of the upper roller 24 faces the feed roller 23, the upper roller 24 separates from the sprocket paper 22. That is, as shown in FIG. 6, the sprocket paper 22 is not pressed,
The force pulled in the direction of arrow D also weakens.

As described above, the sprocket sheet 22 is conveyed by the tractor belt 12, the pin wheel 13, and the platen 4 by increasing or decreasing the force for pulling the sprocket sheet 22 in the direction of arrow D by the upper roller 24, that is, the conveying force of the sheet discharging mechanism 21. Since the tension of the sprocket paper can be maintained at an appropriate level, the pin 16 of the tractor belt 12 coming off the hole of the sprocket paper 22 and the pinwheel 1 inserted into the hole
The distance between the third pin 20 and the third pin 20 can be prevented from increasing.

Next, a second embodiment of the present invention will be described with reference to the drawings. 7 and 8 are side views of a main part showing a second embodiment of the present invention. In FIG. 7, the paper discharge mechanism 31 is composed of a feed roller 32, which is a drive source separate from the platen 4 described in the first embodiment, and an upper roller 33. The feed roller 32 is rotated in the direction of arrow A by a shaft 35 attached to a side of the sheet discharge unit 34. The upper roller 33 is connected to the printer 1
By the shaft 36 attached to the casing (not shown),
It rotates in the direction of arrow A '.

The upper roller 33 has an eccentric shape in which the shaft 36 is shifted from the center, and has a longest outer peripheral portion 37 and a shortest outer peripheral portion 38 on its surface. Further, similarly to the first embodiment, the feed roller 32 and the upper roller 33 have shafts 35 and 36 attached in parallel with each other.
, And are spaced apart without contact. The sprocket paper 22 is sandwiched between the feed roller 32 and the upper roller 33, and is conveyed by rotating the feed roller 32 in the direction of arrow A and the upper roller 33 in the direction of arrow A '. The other components and the transport operation of the printer of the second embodiment are the same as those of the first embodiment, and a description thereof will be omitted.

A paper discharging operation by the paper discharging mechanism 31 of the second embodiment as described above will be described. When the sprocket paper 22 is conveyed, the longest outer peripheral portion 37 and the shortest outer peripheral portion 38 alternately come to a position facing the feed roller 32 by rotating the upper roller 33 in the direction of the arrow A ′.

As shown in FIG. 7, when the longest outer peripheral portion 37 faces the feed roller 32, the upper roller 33 presses the sprocket paper 22 in the direction of the feed roller 32. That is, the sprocket paper 22 is pressed and bent, and the sprocket paper 22 is strongly pulled in the arrow D direction. As shown in FIG.
When the shortest outer periphery 38 of 3 faces the feed roller 32, the upper roller 33 separates from the sprocket paper 22. That is, the force of pulling the sprocket sheet 22 in the direction of arrow D without being pressed is reduced. As described above, by making the upper roller 33 eccentric, the manufacture thereof can be facilitated.

Next, a third embodiment of the present invention will be described with reference to the drawings. FIG. 9 and FIG. 10 are side views of main parts showing a third embodiment of the present invention. In FIG. 9, a paper discharge mechanism 41 includes a feed roller 42, which is a drive source separate from the platen 4 described in the first embodiment, and an upper roller 43.
It is composed of The feed roller 42 is driven by a shaft 45 attached to a side of the paper discharge unit 44.
It rotates in the direction of arrow A. The upper roller 43 is rotated in the direction of arrow A ′ by a shaft 46 attached to a casing (not shown) of the printer 1.

The surface of the upper roller 43 is
7 and the low friction member 48 are alternately covered. The paper friction coefficients of these members are such that the high friction member 47 has μ = 1.0,
The low friction member 48 is set to μ = 0.1. Also,
As in the first embodiment, the feed roller 42 and the upper roller 43 are connected to the shaft 4 mounted in parallel with each other.
5, 46 are provided separately without contact. The sprocket paper 22 is sandwiched between the feed roller 42 and the upper roller 43, and is conveyed by rotating the feed roller 42 in the direction of arrow A and the upper roller 43 in the direction of arrow A '. The other components of the printer according to the third embodiment are the same as those of the first and second embodiments, and a description thereof will be omitted.

The paper discharging operation by the paper discharging mechanism 41 of the third embodiment as described above will be described. When the sprocket paper 22 is conveyed, the high friction member 47 and the low friction member 48 alternately come to a position facing the feed roller 42 by rotating the upper roller 43 in the direction of the arrow A ′.

As shown in FIG. 9, when the high friction member 47 faces the feed roller 42, the sprocket paper 2
2, a feed force is generated, and the sprocket paper 22 is strongly pulled in the direction of arrow D. As shown in FIG. 10, when the low friction member 48 of the upper roller 43 faces the feed roller 42, the feed force acting on the sprocket paper 22 decreases, and the force of pulling the sprocket paper 22 in the direction of arrow D also decreases. As described above, by forming the surface of the upper roller 43 with the high friction member 47 and the low friction member 48, the production thereof can be further facilitated.

[0026]

Since the present invention is configured as described above, it has the following effects.

That is, the continuous paper transport mechanism located downstream of the printing section is constituted by a transport roller located on one side of the continuous paper and a pressing member located on the other side of the continuous paper. The pressing members are arranged so as to separate the portions in contact with the continuous paper on the continuous paper, and the transport roller includes a portion having a large transport force and a small portion with respect to the continuous paper, and the portion having a large transport force and the continuous paper face each other When the continuous paper is flexed and held by the pressing force corresponding to the rigidity of the continuous paper between the portion where the transporting force of the transporting roller is large and the pressing member, and the transporting force of the continuous paper is changed by rotating the transporting roller. By
Since the transport force of the transport mechanism is adjusted so that the tension of the continuous paper is appropriately maintained, it is possible to prevent the line feed printing position from being shifted.

[Brief description of the drawings]

FIG. 1 is a side view showing a first embodiment of the present invention.

FIG. 2 is a perspective view showing the printer of the first embodiment.

FIG. 3 is a side view showing a sheet discharging mechanism of the first embodiment.

FIG. 4 is a top view as seen from the direction of arrow C in FIG. 3;

FIG. 5 is a side view showing a sheet discharging mechanism of the first embodiment.

FIG. 6 is a top view as seen from the direction of arrow C in FIG. 5;

FIG. 7 is a side view of a main part showing a second embodiment of the present invention.

FIG. 8 is a main part side view showing a second embodiment of the present invention.

FIG. 9 is a side view of a main part showing a third embodiment of the present invention.

FIG. 10 is a main part side view showing a third embodiment of the present invention.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 printer 3 print head 4 platen 12 tractor belt 13 pin wheel 16 pin 21, 31, 41 paper discharge mechanism 22 sprocket paper 23, 32, 42 feed roller 24, 33, 43 upper roller 28 convex part 29 concave part 37 longest outer peripheral part 38 shortest Outer part 47 High friction member 48 Low friction member

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) B65H 20/20 B41J 11/26 B41J 15/04 B41J 15/16

Claims (4)

(57) [Claims] 1. A continuous paper which is disposed upstream of a printing section and is provided in the printing section.
The first transport mechanism that supplies
A second transport mechanism for transporting the continuous paper;
The paper transport path between the mechanism and the second transport mechanism has a bent portion.
The transfer speed of the second transfer mechanism is faster than that of the first transfer mechanism.
Printer, the second transport mechanism is located on one side of the continuous paper.
It has a pressing member and a conveying roller located on the other surface side, and the pressing member and the conveying roller respectively contact the continuous paper.
The portions are spaced apart in a direction along the surface of the continuous paper, and the transport rollers have different transport forces with respect to the continuous paper.
A first part and a second part which are continuous with at least a part where the conveying force of the conveying roller is large.
When the paper comes into contact, the pressing member and the transport roller
And the conveying force to the continuous paper is changed by the rotation of the conveying roller.
Printer, characterized in that to reduction. 2. The conveying roller according to claim 1, wherein the unevenness is formed on the surface, and the pressing force is increased when the convex portion faces the continuous paper.
And when the concave portion faces the continuous paper
The printer according to claim 1, wherein the conveying force is reduced by reducing the pressing force . 3. The conveyance roller has an eccentric shape, and increases a pressing force when a longest outer peripheral portion faces continuous paper.
To increase the conveying force by the shortest outer periphery continuous sheet
Transport force by reducing the pressing force when facing
The printer according to claim 1, wherein the size is reduced . 4. A high-friction member and a low-friction member are formed on the surface of the transport roller, and when the high-friction member comes into contact with the continuous paper.
When the low friction member comes in contact with continuous paper
2. The printer according to claim 1 , wherein the conveying force is reduced .