JPS63209962A - Paper pressing mechanism of printing apparatus - Google Patents

Abstract

PURPOSE:To obtain a proper pressing force, by constituting the title mechanism of a drive roller for feeding paper and a paper guide for receiving the paper fed by said roller and having a leading end arranged in the vicinity of a printing position so as to be made freely revolvable around a support shaft corresponding to the rigidity of the paper and pressing the paper by the above mentioned leading end. CONSTITUTION:Paper 22 is fed by a drive roller 15 and the leading end of the paper 22 is brought into contact with the guide piece 20 of a paper guide 18. Whereupon, the paper 22 pushes up the whole of the paper guide by its stiffness to gradually revolve the paper guide 18 around a support shaft 14 in a counterclockwise direction. Then, the leading end 20a of the guide piece is brought into contact with the outer periphery of a platen 10. At the same time, the paper 22 is guided along the paper guide 18 to enter between the platen 10 and the leading end 20a and pressed by the leading end 20a. Since the paper guide 18 generates moment of rotation having the magnitude corre sponding to the rigidity of the paper 22 and presses the leading end 20a to the platen 10 by said moment, the paper can be pressed by the force correspond ing to the rigidity of the paper.

Description

[Detailed description of the invention] - The present invention is applicable to printing devices such as printers, plotters, and typewriters that transport paper toward a platen, set the paper on the outer periphery of the platen, and sequentially print on the paper on the platen. Specifically, the present invention relates to a paper holding mechanism that prevents paper from lifting off the outer periphery of a platen in such a printing device.

Conventionally, in this type of printing device, as shown in Fig. 8, mylar (2) was attached to the tip of the paper guide frame (1).
) is fixed by adhesive etc., and the fixed mylar (2
) is pressed against the platen (3). Therefore, when setting paper, the paper is fed manually or by an automatic paper feeder to be fed between the feed roller (4) and the pressure roller (5), and the feed roller (4) is rotated to feed the paper (6). ), and the paper (6)
Guide the tip of the paper (6) to the printing position on the outer periphery of the platen (3) with the fixed mylar (2), and then guide the paper (6) with the fixed mylar (2).
The tip was set to press against the outer periphery of the platen (3).

1 Problem to be Solved by the Invention As described above, conventionally, Mylar (2) is fixed to the paper guide frame (1), and the fixed Mylar (2) always applies a constant force to the paper (6) to the platen (3). ). However, according to this conventional paper holding mechanism, even if the rigidity of the paper supplied to the platen (3) varies depending on the thickness and paper quality, the same pressing force is always applied to the paper. If the pressure is too weak against paper with strong rigidity, the paper will float up as shown by the dashed-dotted line in Figure 1, and on the other hand, if the pressure is too strong against paper with low rigidity, the conveyance of the paper will be hindered. was occurring.

Therefore, an object of the present invention is to provide a paper holding mechanism that can apply an appropriate pressing force corresponding to the rigidity of the paper fed to the platen.

Therefore, as shown in the illustrated embodiments below, the paper holding mechanism of the present invention uses the drive roller (15) shown in FIGS. 1 to 4 to convey the paper (22). ) or a platen (24) shown in FIG. 7, and a paper conveying roller such as a platen (24) shown in FIG. It is rotatable around the support shaft (14) according to the rigidity of the paper (22) to be received, and the paper (z2)
When the rigidity is strong, it is strong, and when it is weak, it is weak.
Paper guide (18) that presses the paper (22) with a)
It is characterized by consisting of.

Raw--1 However, the paper (
22), rotate the paper guide (18) according to the rigidity of the paper (22) to be received, and rotate the paper guide (18) to
a) is pressed against the platen (10) or (24), and its tip (20a) is pressed against the paper (22).

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below based on embodiments of the present invention shown in the drawings.

FIG. 1 shows a case where the paper holding mechanism of the present invention is applied to a digital serial printer. In FIG. 0, the reference numeral (10) indicates a platen. The code (11) is.

It is a hammer that strikes the type (12a) on the outer periphery of the type wheel (12) and hits it against the platen (10) via the print ribbon (13).

In the illustrated embodiment, a support shaft (14) rotatably supported at both ends by a side frame (not shown) and disposed parallel to the platen (10) is attached to a drive roller (
15) Attach. A driven roller (17), which is rotatably attached around an attachment shaft (16), is pressed against this drive roller (15).

A paper guide (18) is attached to the support shaft (14) of the drive roller (15) so as to be rotatable about the support shaft. The paper guide (18) includes an arm (19) rotatably attached to the support shaft (14), and a base end fixed to the arm (19) with the tip (20a) facing the printing position on the platen (10). Extendable, lightweight and thin plate-like guide piece (20
), but the paper guide (18) always generates a moment of rotation clockwise in the figure due to its own weight,
The arm (19) is stopped against the stopper shaft (21). Then, as will be described later, the angle at which the leading edge of the paper (22) passes between the driving roller (15) and the driven roller (17) and hits the rear paper guide (18) is adjusted to an acute angle (θ) as shown in FIG. so that the leading edge of the paper (22) always guides in the printing direction.

However, when it is desired to set the paper (22) on the outer periphery of the platen (10) using the paper holding mechanism configured as described above, first, the paper (22) is fed manually or by an automatic paper feeder, and then the drive roller (15) and the driven roller (17).

Then, the drive roller (15) is further rotated to
), and move the leading edge of the paper (22) to the paper guide (18).
the guide piece (20). When the leading edge of the paper (22) hits, the paper (22) pushes up the entire paper guide (18) due to its stiffness, and gradually pushes the paper guide (18) up the support shaft (14) as shown in Figure 3. Rotate counterclockwise around the center. Then, the tip of the guide piece (20
a) to the outer periphery of the platen (10). At the same time, the paper (22) is guided along the paper guide (18) and sent upward while being curled. Eventually, the sheet of paper (22) gets between the platen (10) and the leading edge (20a).
) is held down by the tip (20a).

By the way, the paper guide (18) is pushed up by the paper (22) and generates a rotational moment corresponding to the rigidity of the paper (22), thereby causing the guide piece (2
Since the tip (20a) of 0) is pressed against the platen (10), for example, if a highly rigid paper is fed, the paper guide (18) will press the paper as strongly as possible according to the rigidity of the paper. In addition, in the case of paper having low rigidity, the paper guide (18) will press down on the paper weakly corresponding to the rigidity of the paper.

In this printer, paper (
22) to the platen (10), and the paper (22)
after setting it by pressing it on the platen (10).

Move the carriage (not shown) and move the platen (10
), the selection motor mounted on the carriage rotates the type wheel (12), selects the desired type among the type characters (12a) on the outer periphery of the type wheel (12), and Hammer (1) the type (12a)
1) and pass the print ribbon (13) through the platen (1).
paper (22) on the platen (10).
) are printed sequentially.

Incidentally, in the embodiment shown in FIGS. 1 and 2 described above, the paper guide (18) is not provided with a biasing means, so that when the paper (22) is conveyed, the leading edge of the paper guide (18) is not provided. The guide piece (20) is stopped against the stopper shaft (21) until it hits the guide piece (20). However, in this invention, as shown in FIG. 4, for example, a spring (
23) is attached to one end, and its spring (23) gives the entire paper guide (18) the habit of always rotating counterclockwise in the figure around the support shaft (14).

The paper guide (18) may be biased in the direction of pressing the guide piece tip (20a) against the platen (lO) and held so as not to move due to vibration or the like.

Further, in the above embodiment, the tip end (20a) of the guide piece of the paper guide (18) is formed flat.

However, in this invention, as shown in FIG. 5, the tip (20a) of the guide piece of the paper guide (18) is
In that case, the paper (22) may be curled to match the outer peripheral surface of the paper (22) to prevent it from rising.

For example, as shown in FIG.
a) may be formed at appropriate intervals.

Further, in the above embodiment, a drive roller (15) is provided as a paper transport roller, and the drive roller (15) is rotated to send the paper (22) to the platen (10).
The present invention was applied to a printer in which a platen (10) is provided separately from the drive roller (15). However, this invention uses a platen (24) that is common to the drive roller (15) described above, as shown in FIG. 7, for example.

It can be applied to a printer configured to press the driven roller (7) against the platen (24) and rotate the platen (24) to convey the paper (22). In other embodiments, for example, the paper guide (18)
Attach the support shaft (14) to a side frame (not shown), attach a spring (23) to the arm (19) of the paper guide (18), and use the spring (23) to push the tip of the guide piece (20a) against the paper (22). Force in the direction of pressing.

Note that in the embodiments described above, the case where the present invention is applied to a serial printer has been described. However, the present invention is not limited to printers, and can be similarly applied to other printing devices such as typewriters and plotters.

Therefore, according to the present invention, in such a printing device, the paper guide is rotatable according to the rigidity of the paper to be received, so that the paper guide can be rotated depending on the thickness and quality of the paper supplied to the platen. You can always press the paper with an appropriate pressing force, such as pressing it hard at times and pressing it weakly at other times.

[Brief explanation of the drawing]

1 to 7 show an embodiment in which the present invention is applied to a digital serial printer.
The figures are side views showing one embodiment of the paper holding mechanism of the present invention, in which Fig. 1 shows the state immediately before the paper hits the paper guide, Fig. 2 shows a partially enlarged view, and Fig. 3 shows the state immediately before the paper hits the paper guide. indicates the state in which the paper is guided by the paper guide and pressed against the outer periphery of the platen. 4 to 7 respectively show other embodiments of the present invention, of which FIG. 4 shows the embodiment shown in FIGS. 1 to 3, particularly when a means for urging the paper guide is provided. 5 is a side view showing the case where the tip of the paper guide is curled, FIG. 6 is a partially enlarged view showing the case where the curled tips of the paper guide are formed with intervals, and FIG. 7 is a side view showing the case where the curled paper guide tip is formed at intervals. It is a side view which shows the case where a roller is a platen. FIG. 8 is a schematic side view showing a conventional paper holding mechanism.

Claims (1)

[Claims] 1. A paper transport roller that transports paper, and a paper transport roller that receives the paper that is transported by the paper transport roller and is arranged so that its leading edge is located near the printing position, and that the paper transport roller receives A paper holding mechanism for a printing device, comprising a paper guide that is rotatable about a support shaft and presses the paper with its tip in a manner that is strong when the paper is rigid and weakly when the rigidity of the paper is weak. 2. A paper holding mechanism for a printing device according to claim 1, wherein a platen is provided separately from the paper conveyance roller, and the tip of the paper guide is arranged close to the platen. 3. The central axis of the paper transport roller is the support shaft,
The paper holding mechanism of the printing device according to claim 2, wherein the paper guide is rotatable about its support shaft. 4. The paper holding mechanism of the printing device according to claim 1, wherein the paper transport roller is a platen, and the tip of the paper guide is disposed close to the platen. 5. A paper holding mechanism for a printing device according to claim 1, wherein the paper guide is biased in a direction in which its leading end presses the paper. 6. The paper holding mechanism of the printing device according to claim 1, wherein the tip of the paper guide is curled in the direction of holding the paper.