JPH05238618A - Paper feeding device - Google Patents

Abstract

PURPOSE:To surely remove curl by giving stable back tension to a paper sheet. CONSTITUTION:When the diameter of a roll paper 10 is large, the roll paper is unwound at a high position, which stabilizes a paper pressing bar 19 of an arm 20 at a comparatively high position. At this time, this causes a large difference in angle between in the direction in which a spring 22 is energized and the direction in which the working point of the spring 22 works, and the energizing force of the spring is not efficiently transferred. Therefore, the lower direction pressing force given to the paper pressing bar 19 of the arm 20 is small. On the contrary, in the case of a small diameter, the roll paper is unwound at a low position, which stabilizes the paper pressing bar at a comparatively low position. At this time, the difference in angle is comparatively small, efficiently transferring the energizing force of the spring to the arm 20. Therefore, the lower direction pressing force given to the paper pressing bar 19 is large. For this reason, with the reduction of the mass of the roll paper, the friction caused by a friction member becomes large, as a result, stable back tension can be obtained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sheet feeding device.

[0002]

2. Description of the Related Art Generally, a recording paper is used in a paper feeding device, and the recording paper is a roll paper wound around a cylindrical core. Therefore, the fax machine is equipped with a curl removing device for removing the curl of the roll paper.

The curl removing device removes the curl by utilizing the tension for pulling the roll paper to fold the curl in the direction opposite to the curl direction.

[0004]

However, since the weight of the roll paper is different at the beginning and at the end of use, the tension for removing the curl is different and the curl removal is not constant.

The present invention has been made in view of the above problems, and it is an object of the present invention to provide a paper feeding device capable of keeping the curl constant.

[0006]

SUMMARY OF THE INVENTION The present invention comprises a roll paper tray for rollably storing roll paper, and a curl removing device for removing the curl of the roll paper drawn from the roll paper tray. A device, a guide friction member provided along the conveyance path of the roll paper tray, which abuts and guides the roll paper, and a friction force of the guide friction member with respect to the roll paper according to the diameter of the roll paper. And a tension adjusting member for adjusting.

[0007]

When the roll paper is large, since the area where the roll paper contacts the guide friction member by the tension adjusting member is small, the back tension due to the guide friction member does not act, and only the back tension due to the weight of the roll paper acts. To do.

Further, when the roll paper is small, since the area where the roll paper comes into contact with the guide friction member by the tension adjusting member is large, the back tension due to the guide friction member acts and the self-weight of the roll paper becomes light. A certain amount of back tension acts.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of the present invention will be described below with reference to the accompanying drawings. FIG. 1 is a sectional view of a sheet feeding device according to the present invention. In the figure, reference numeral 1 is a document tray, and the document sheets set on the document tray 1 are fed by a paper feed roller 2
And a separation sheet sheet (not shown) made of rubber, which is pressed against the sheet feeding roller 2 with a constant pressure, to separate the sheets one by one by the original sheet separation feeding mechanism A, and It is sent to the reading section B. Then, it is sandwiched between the pressure contact roller 4 and the paper feed roller 5 provided in the reading section B, and comes out from the light source 7 arranged between the paper feed roller 5 and the paper discharge roller 6 to output the original paper. The reflected light is reflected by the two mirrors 8a and 8b and is input to the CCD 9 for reading, and the read original sheet is discharged from the sheet discharge roller 6 to the outside.

An upper cover 30 is provided on the upper rear surface of the paper feed so as to be opened and closed by rotating around an axis (not shown). A recording section C is attached to the back side of the upper cover 30. A roll paper tray 11 for storing the roll paper 10 is installed in the vicinity of the recording section C,
A curl removing device D is arranged between the roll paper tray 11 and the recording section C.

FIG. 2 is an enlarged view of a main part of the paper feeding device according to the present invention. A flange portion 30a is formed on the back side (the lower side in the figure) of the upper cover 30, and the thermal head holding plate 13 and the curl removing plate 14 are fixed to the flange portion 30a with screws 12. A thermal head 16 is provided on the lower surface side of the thermal head holding plate 13 via a spring 15.
The thermal head 16 is provided with a spring 15
Is always urged downward in the figure. A platen roller 17 is provided below the thermal head 16 in the figure, and the thermal head 16 is pressed against the platen roller 17 by a spring 15. A bent portion 14a is formed on the curl removing plate 14, and the curl is removed when the roll paper 10 passes through the bent portion 14a. A rubber resistance member 18 is attached to the end of the roll paper tray 11 on the roll paper discharge side (right side in FIG. 2). In the vicinity of the friction member 18, an arm 20 having a paper pressing bar 19 for pressing the roll paper at one end is swingably provided on a side plate frame (not shown) via a pin 21. Further, a spring 22 is provided at the other end of the arm 20 so as to constantly urge the arm 20 around the pin 21 in the clockwise direction in the figure. When the weight of the roll paper 10 is large, the elastic force of the spring 22 suppresses the rotation of the arm 20 around the pin 21 in the clockwise direction, but when the weight of the roll paper 10 is small. The arm 20 is rotated to a certain extent so that the paper pressing bar 19 can come into contact with the friction member 18 as shown in FIG.

In the paper feeding device having the above-described structure, the roll paper 10 is brought into contact with the paper pressing bar 19 and is conveyed to the bent portion 14a of the curl removing plate 14 via the friction member 18, where it is curled. The curl is removed because it is bent in the opposite direction and pulled in the directions A and B in FIG. 2 with a certain size. Further, the decurled roll paper 10 is conveyed between the thermal head 16 and the platen roller 17, and is printed there. Then, it is discharged to the standby paper tray 23 (FIG. 1) and cut by a cutter (not shown).

In order to perform the curl removal stably in the above apparatus, it is desirable that the back tension of the roll paper 10 at the position of the curl removing plate 14 which is the curl removing apparatus is substantially constant.

The angle of the arm 20 depends on the spring 22.
Stabilizes when the urging force of and the tension of the roll paper are balanced. By the way, when the diameter of the roll paper 10 is large, the position where the roll paper 10 is unwound, that is, the position of the top of the roll in the figure is high. Therefore, the paper presser bar 19 of the arm 20 should be stabilized at a relatively high position. become. At this time, a large angular deviation occurs between the biasing direction of the spring 22 and the working direction of the action point of the spring 22, and the biasing force of the spring is not efficiently transmitted to the arm 20. Therefore, the paper holding rod 1
The downward pressing force applied to the roller 9 is small, and the arm 20 does not rotate so much, so that the area where the roll paper 10 contacts the friction member 18 is small. Therefore, the force in the direction of arrow A in FIG. 2 acts on the weight of the roll paper 10 itself, and this force acts as back tension.

When the diameter of the roll paper 10 becomes smaller, the position at which the roll paper 10 is unwound, that is, the position of the top of the roll in the figure is lower, so that the paper pressing rod 1 of the arm 20 is lowered.
9 will be stable at a relatively low position. At this time,
The angular deviation between the biasing direction of the spring 22 and the working direction of the action point of the spring 22 is relatively small, and the biasing force of the spring is efficiently transmitted to the arm 20. Therefore, the downward pressing force applied to the paper pressing bar 19 is large, and the arm 20 is rotated clockwise about the pin 21 by the urging force of the spring 22,
As shown in FIG. 3, it rotates to a position where it abuts on the friction member 18. Therefore, the area where the roll paper 10 contacts the friction member 18 increases. Then, even if the weight of the roll paper 10 itself becomes light, the force in the direction of arrow A in FIG.
Back tension acts by.

[0016]

As described above, according to the present invention, the curl can be removed depending on whether the curl of the roll paper is large or small, and the back tension at each time is almost uniform. There is an effect that can be done.

[Brief description of drawings]

FIG. 1 is a sectional view of a sheet feeding device according to the present invention.

FIG. 2 is an enlarged view of a main part of the paper feeding device according to the present invention.

FIG. 3 is an enlarged view of a main part of the paper feeding device according to the present invention.

[Explanation of symbols]

 10 ... Roll paper 11 ... Roll paper tray 18 ... Friction member 19 ... Paper pressing bar (tension adjusting member) 20 ... Arm (tension adjusting member) 22 ... Spring (tension adjusting member)

Claims (1)

[Claims] 1. A roll paper tray for storing roll paper rollably and a curl removing device for removing the curl of the roll paper pulled out from the roll paper tray by pulling the roll paper in a direction opposite to the curl direction. A sheet feeding device provided with,
A guide friction member that is provided along the conveyance path of the roll paper tray and that contacts and guides the roll paper, and a tension adjustment that adjusts the friction force of the guide friction member with respect to the roll paper according to the diameter of the roll paper. A sheet feeding device comprising: a member.