JPH0245179A - Printer - Google Patents

Abstract

PURPOSE:To obtain a printer of a roller arranging structure in which conveyance of a cutform is certainly performed by a method wherein a pressure roller is arranged on an upper side of a feed roller near a printing part. CONSTITUTION:When a cutform 11 is inserted from a left direction to a right direction, it takes a form of coming in contact with a pressure roller 32 after touching the pressure roller near a crest (a) of a feed roller 32 after touching the pressure roller near a crest (a) of a feed roller 31, and the feed roller 31 generates force conveying the cutform 11 in the right direction. Though reaction force by which the cutform 11 is pushed back in the left direction is generated since the cutform 11 comes in contact with the pressure roller 32, this reaction force is canceled by force generated by contact of feed roller 31 with the cutform 11. The cutform 11 is pinched between both rollers 31, 32 and is certainly conveyed by sucking in a right printing head direction. Since the cutform 11 is so constructed as to comes certainly in contact with the feed roller 11, even though the cutform 11 is inserted slightly aslant, the cutform 11 is sucked by being pinched.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a printer, and more particularly to an arrangement structure of pressure rollers and feed rollers that allows a cut sheet to be smoothly conveyed to a printing section.

[Conventional technology]

Conventionally, in printers using the horizontal inserter method, in which a cut sheet (hereinafter abbreviated as a cut sheet) is moved horizontally relative to the printing section, the axis of the pressure roller is positioned directly above the axis of the feed roller. There is.

That is,! Apart from any errors or play, the line connecting the contact point of both rollers and the point of wire collision of the printing head against the platen of the printing section is almost perpendicular to the perpendicular line passing through the axes of both rollers. There is.

In addition, as an example of this type of printer, Japanese Patent Laid-Open No. 55
There is a publication No.-146778.

[Problem to be solved by the invention]

In a conventional printer, as shown in FIG. 9, a feed roller 31 and a pressure roller 32 pressed down by a spring 33 are used.
Since the cut sheet 11 of thickness T is inserted horizontally to the right in the figure into the contact point a of Even though both rollers 31 and 32 are rotating in the direction of the arc-shaped arrow to convey the ticket 11 to the right, they contact the pressure roller 32 at an angle θ, so the ticket 11 receives a leftward reaction force f. is generated, and the cut sheet 11 is transferred to both rollers 31
, 32, and the ticket 11 is not sucked into a printing section (not shown) located on the right side of both rollers 31, 32. This tendency becomes more pronounced as the thickness T of the cut sheet 11 increases.

Further, as shown in FIG. 10, the weight of the cut sheet 11 is applied to the feed roller 31 by the pressure roller 32 with a friction coefficient of μm between the W cut sheet 11 and the paper table 2 of the printer. Assuming that the pressing force is F and the coefficient of friction between the cut sheet 11 and the feed roller 31 is μ2, the condition for the cut sheet 11 to be sucked between both rollers 31° and 32 under pressure is W×μm<
This is when the condition FXμ2 is satisfied. however,
The pressing force F is determined by the printing operator pressing the cut sheet 11 with both rollers 31°3.
This occurs when the printing operator inserts the cut sheet 11 slightly diagonally between both rollers 31 and 32, so that the cut sheet 11 and the feed roller 31
due to the small contact area.

The pressing force F becomes small, and the ticket 11 is not easily sucked into the printing section. Note that 6 in FIG. 3 is a paper guide.

Incidentally, the reason why the friction coefficient between the pressure roller 32 and the cut sheet 11 is not taken into account is because the pressure roller 32 is made of a material (for example, polyacetal) that makes the friction coefficient between the pressure roller 32 and the cut sheet 11 extremely small. This is because there is.

The reason for using such a material is that the cut sheet 11 is made of both rollers 31.
, 32 and the printing section, the purpose is to prevent the text on the slip 11 from becoming difficult to read due to the printing on the slip being transferred to the pressure roller 32 due to friction. .

Accordingly, an object of the present invention is to provide a printer having a roller arrangement structure in which sheets can be transported reliably.

[Means to solve the problem]

A feature of the present invention that achieves the above object is that the pressure roller is disposed above the feed roller and closer to the printing section.

Further, in the present invention, a paper pressing roller is provided above the feed roller so that the contact between the cut sheet and the feed roller is further increased. It is preferable to arrange the paper holding roller so that it does not compete with the pressure roller.

[Effect]

In the printer of the present invention, by providing the pressure roller near the printing section, the cut sheet and the feed roller come into contact with each other reliably, and then the cut sheet contacts the pressure roller. Even if a reaction force f is generated to push back the sheet, the reaction force f is canceled by the conveyance force generated by the contact between the feed roller and the cut sheet, and the sheet is conveyed toward the printing section.

The contact between the feed roller and the cut sheet is made more reliable by pressing with the paper presser roller, and the conveyance becomes stronger.

〔Example〕

FIG. 1 schematically shows a printer according to an embodiment of the present invention.

In the figure, 1 is a print head from which dot wires protrude downward, 2 is a paper table on which a cut 11 is placed, 3 is a cut transport roller device that transports the cut 11 to the print head 1 side,
4 is a pull tractor that conveys the continuous paper 12; 5 is a platen that is provided opposite to the print head 1 and receives the impact force of the print head 1; and 6 is a paper guide.

The paper slip 11 is transported back and forth between the paper tray 2 and the print head 1 as indicated by arrow A. The continuous paper 12 is conveyed rightward in the figure as indicated by arrow B.

As shown in the figure, the conveyance paths of the cut sheet 11 and the continuous paper 12 are separated, and the path of the cut sheet 11 is located above the path of the continuous paper 12, so that the continuous paper 12 is transported between the print head 1 and the platen. It is possible to print on the cut sheet 11 while it is set between 5 and 5.

Note that print head 1. Single sheet conveyance roller device 3゜pull 1-
Rakuta 4. Although illustration of the drive mechanism of the platen 5 is omitted to simplify the drawing, each part is interconnected and driven in accordance with the print mote of the print head 1. Further, an ink ribbon is provided between the print head 1 and the base 11 or the continuous paper 12, but it is not shown.

FIG. 2 shows an enlarged view of the positional relationship between the feed roller 31 and the pressure roller 32 in the cut conveyance roller device [3. Print head 1 is.

In FIG. 2, it is located on the right side of the pressure roller 32. That is, in the present invention, the pressure roller 32 is arranged closer to the print head 1 than the feed roller 31 is. That is, the perpendicular line passing through the axis of the pressure roller 32 is C from the perpendicular line Yd-Yd passing through the axis of the feed roller 31.
The print head is closer to 1 by 1 minute. Note that 33 is a spring.

Therefore, when the cut 11 is inserted from the left to the right in the figure, it comes into contact with the pressure roller 32 after coming into contact with the feed roller 31 near the apex a. Since the feed roller 31 is made of a material with a large friction coefficient μ2 (for example, urethane rubber), the feed roller 31
1 generates a force (self-weight W of the cut 11×friction coefficient μ2 of the feed roller 31) to convey the cut 11 rightward in the figure.

Even if the cut 11 comes into contact with the pressure roller 32 and generates a reaction force f that pushes the cut 11 back to the left as shown in FIG.
The force generated by the contact between the feed roller 31 and the cut sheet 11 (
This reaction force f is canceled by the above W×μ2), and the cut sheet 11 is moved by both rollers 31. , 32, and is reliably sucked and conveyed toward the right print head. Single sheet 11 is feed roller 3
1, so even if the ticket 11 is inserted slightly obliquely, the ticket 11 will be sucked under pressure. Further, when the printing operator inserts the ticket, there is no need to take care to ensure that the ticket 11 is sucked in.

FIGS. 3 to 5 show an embodiment in which paper press rollers are provided to ensure the suction and pressure of the cut sheet.

As shown in FIG. 3, the paper pressing roller 41 rotates following the feed roller 31.
Arm 42. It is supported by a shaft 43. The arm 42 itself is supported via a shaft 44 by a frame 45 that is integrated with the paper guide 6. The center of rotation of the feed roller 31 and the paper holding roller 41
The gap between the perpendicular lines passing through the center of rotation is E2.

The left end of the arm 42 is supported by a frame 45 through a shaft 44, and the right end, which supports the paper pressing roller 41, is a free end. Note that FIG. 4 shows the paper pressing roller 41. The arm 42 is shown viewed from above. As shown in FIG. 5, the pressure roller 32 and paper holding roller 41 are installed at positions shifted from each other with respect to the feed roller 31 so as not to compete with each other.

When the ticket 11 is inserted in the right direction as shown in FIG. 3, the insertion force at this time lifts the paper press roller in the direction of the arrow y, and the dead weight W of the paper press roller 41 is applied to the ticket 11. The product of the paper presser roller's own weight W and the friction coefficient μ2 between the cut sheet 11 and the feed roller 31 acts as a force that moves the cut sheet 11 to the right. Therefore, the cut sheet 11 is more reliably fed to the feed roller 31 and the pressure roller 32.
The paper is pinched by the paper and is sucked and conveyed toward a printing section on the right side (not shown).

Note that the pressure roller 32 and feed roller 31 should be
Paper pressing roller 41 and feed roller 3
In order to keep the clamping force between the two sheets small, the weight of the paper pressing roller 41 is set to an appropriate value. According to experiments conducted by the present inventors, the force applied to the cut sheet 11 by the paper pressing roller 41 was preferably about 10 grf. Like the pressure roller 32, the paper pressing roller 41 preferably has a small coefficient of friction to prevent printing from being transferred, and for example, one made of polyacetal was used. Also, the eccentricity ε1 of the pressure roller 32 and the paper pressing roller 41 that does not interfere with the suction and ejection of the ticket 11 is set. ε2 is 10 to 15% of the diameter of the feed roller 31.

6 to 8 show alternatives to the paper press roller.

In the embodiment shown in FIG. 6, a spring 20 is attached to the shaft 34 of the pressure roller 32. In the embodiment shown in FIG. 7, the presser plate 21 is attached to the shaft of the pressure roller 32. The spring 20 and the presser plate 21 in both embodiments are both relative to the shaft 34.

It can be rotated freely. Also, spring 20. The point where the presser plate 21 contacts the feed roller 31 is on the left side of the apex a of the feed roller 31 by an amount of deviation ε2, and the pressure roller 32 is closer to the right side of the print head by an amount of ε1.

In the embodiment shown in FIG. 8, a medium 22 such as an elastic neutralizing brush or plate is placed at a position of deviation E2 with respect to the paper guide 6.
has been established.

In either embodiment, a straight line passing through the axes of the feed roller 31 and the pressure roller 32 is oblique to the conveyance direction of the cut 11, and the feed roller 31 is closer to the print head.

Even in the case of an insert method in which the cut sheet 11 is inserted into the feed roller 31 from diagonally above.

By establishing this relationship, the ticket is reliably pinched and conveyed between the feed roller and the pressure roller.

〔Effect of the invention〕

As described above, according to the present invention, it is possible to obtain a printer having a roller arrangement structure in which sheets are reliably conveyed.

[Brief explanation of the drawing]

FIG. 1 is a schematic cross-sectional view of a printer showing an embodiment of the present invention, FIG. 2 is an enlarged view of the sheet conveying roller device of FIG. 1, and FIG. 3 is a schematic cross-sectional view of a printer showing an embodiment of the present invention. FIG. 4 is a top view showing the paper press roller used in the cut sheet conveying roller device of FIG. 3, and FIG.
6 to 8 are diagrams showing other embodiments of the cut sheet conveying roller device shown in FIG. FIG. 3 is a diagram showing the state of sheet conveyance in the printer. DESCRIPTION OF SYMBOLS 1... Print head, 2... Paper table, 3... Cut conveyance roller device, 5... Platen, 6... Paper guide, 11... Cut sheet, 31... Feed roller , 32・
・・・Pressure Japanese Pattern 3 Figure 6 Ward 1 High School Figure 8

Claims (1)

[Claims] 1. In a printer that pinches paper between a pressure roller and a feed roller and conveys the paper to a printing unit by rotating both rollers, the pressure roller is made of a material with a smaller coefficient of friction than the feed roller. is arranged above the feed roller and on the printing section side. 2. In a printer that pinches paper between a pressure roller and a feed roller and transports the paper to the printing section by rotating both rollers, the pressure roller is made of a material with a smaller coefficient of friction than the feed roller and is placed above the feed roller. Moreover, the printer is characterized in that a paper presser roller is disposed on the printing unit side and is further provided above the feed roller and on the opposite side from the printing unit to press the paper against the feed roller with a slight force. 3. The printer according to claim 2, wherein the paper pressing roller is made of a material having a smaller coefficient of friction than the feed roller. 4. The printer according to claim 2, wherein the paper pressing roller presses the paper against the feed roller by its own weight. 5. The printer according to claim 2, wherein the paper clamping force between the paper press roller and the feed roller is smaller than the paper clamping force between the pressure roller and the feed roller. 6. In a printer that conveys the paper to the printing unit by pinching the paper between a pressure roller and a feed roller and rotating both rollers, the straight line passing through the axes of the feed roller and pressure roller is relative to the paper conveyance direction. A printer characterized in that the pressure roller is located near the printing section, and the pressure roller is located above the feed roller.