JPH06179277A - Mechanism for correcting curling of leading end of roll paper - Google Patents

Abstract

PURPOSE:To correct the curling small in radius of curvature of the leading end of roll paper even when the diameter of the roll paper is reduced by providing a means curving the roll paper in the lateral direction thereof to the terminal part of a roll paper feed guide. CONSTITUTION:When roll paper is cut at the beginning of use or on the way of use, the leading end of the roll paper necessarily enters the gate 8 of a roll paper taking-up mechanism 7 from feed guides 4, 6. When the leading end of the roll paper 1 becomes a curled state by the winding habit of the roll paper not to straightly enter the gate part 8 and, especially, the residual quantity of the roll paper is little, the diameter of the roll paper becomes small and the curling degree thereof is increased and the leading end of the roll paper does not enter the gate 8. Then, a projection 5 is provided in the vicinity of the terminal of the feed guide 4 and a notch 9 is provided to the feed guide 6 at the part opposed to the projection 5 to correct the curling of the leading end of the roll paper 1 to well guide the leading end of the roll paper 1 to the gate part 8.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a roll paper tip for accurately guiding the roll paper tip to a winding mechanism in a transport path of a printer such as a journal printer that uses roll paper as a printing sheet. Related to the curl correction mechanism.

[0002]

2. Description of the Related Art Conventionally, as a means for preventing a paper jam (jam) caused by the tip of a curled roll paper being caught in a gate, for example, Japanese Patent Laid-Open No. 63-165.
There is one disclosed in Japanese Patent No. JP 63-1
In the one disclosed in Japanese Patent No. 65164, after the roll paper is cut by a cutter, the roll paper is conveyed to the gate before the curl becomes tight (curvature radius becomes small) due to moisture or the like. This was to prevent paper jams.

[0003]

The above prior art utilizes the fact that it takes time from the cutting of the roll paper tip to the curling when the cause of the curl is moisture. However, there is a problem that it is effective when the cause of curl at the tip of the roll paper is moisture etc., but it cannot be applied when the roll paper originally has a small diameter and the curl is tight. The object of the present invention is to specify a curl having a small radius of curvature at the tip of the roll paper when the diameter of the roll paper is originally small and the roll paper is used up to near the end so that the curl having a small radius of curvature is corrected. The purpose is to correctly guide the position gate without causing a jam.

[0004]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention rolls a roll paper on the outer end of a roll guide of a roll guide, to be precise, just before the end. A means for bending in the width direction of the paper is provided.

[0005]

The leading end of the roll paper tends to be curled in the space between the transport path and the gate due to the curling of the roll paper. When deformed into a convex shape when viewed from the direction of travel of the roll paper, the end of the roll paper is conveyed straight through the gap to the gate. In particular, when the projection means is formed by the notch as the bending means, when the tip of the roll paper passes through the projection-shaped portion provided on the conveyance guide on the outside of the curl shape, the roll paper is Of the conveyance guide and the notch shape of the other conveyance guide, the force is received and deformed to a convex shape toward the notch shape when viewed from the roll paper advancing direction. The curl at the leading end of the roll paper is straightened, and the leading end of the roll paper is conveyed straight through the gap to the gate. If the roll paper is wide and the curls on both ends of the roll paper cannot be completely corrected with the pair of protrusions and notches provided in the central portion in the roll paper width direction, a plurality of pairs of protrusions and The cutout shape corrects the curl over the entire width of the roll paper. Also,
The curl straightening force increases the conveyance resistance of the roll paper, but by configuring the protrusions with an elastic body, the protrusion force is slightly reduced by the conveyance force of the paper after passing the leading edge of the roll paper. The transport resistance can be reduced as compared with the case of a rigid protrusion.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. FIG. 1 is an overall schematic view of an embodiment of the present invention. In FIG. 1, a roll paper 1 is printed by a print head 2 in a platen section 3, and the printed roll paper 1 passes between a lower conveyance guide 4 and an upper conveyance guide 6 to wind up the rolled paper. The mechanism 7 sequentially winds. By the way, when the roll paper 1 is started to be used or the roll paper 1 is cut midway, the leading end of the roll paper 1 is rolled from the transport guides 4 and 6.
The roll paper take-up mechanism 7 must enter the gate portion 8, but the curl of the roll paper 1 causes the leading end to become a curl, so that the roll paper 1 cannot enter the gate portion 8 straight. In particular, when the remaining amount of the roll paper 1 is small, the roll diameter of the roll paper becomes small and the curl becomes tight (the radius of curvature is small) so that the roll paper 1 does not enter the gate 8.

Therefore, as shown in the perspective view of FIG.
By providing the notch 9 in the portion facing the projection 5, the curl at the tip of the roll paper 1 can be corrected and guided to the gate portion 8 well. An explanation of this action is shown in FIG. In FIG. 3, when there is no protrusion 5, the leading end of the roll paper 1 fed past the ends of the transport guides 4 and 6 is in the shape of a curl due to the gap to the roll paper winding mechanism 7. It cannot be guided well to the gate. However, by providing the protrusion 5 at the central portion of the lower conveyance guide 4 in the roll paper width direction and the notch 9 at the portion facing the protrusion of the upper conveyance guide 6, the roll paper 1 is in the curling direction. The curl at the tip of the roll paper 1 can be straightened by forcibly and gently curving in the vertical direction.

When the width of the roll paper 1 is wide, it is not possible to bend the roll paper 1 over the entire width by one projection in the central portion in the width direction, and it is possible to correct the curl of both ears at the tip. Although not possible, it can be solved by arranging two protrusions 5 in the width direction. By the way, since the roll paper 1 is curved straightly in the width direction of the roll paper, even after the leading end of the roll paper 1 passes through the protrusion 5, the roll paper 1 is not covered by the protrusion 5 and the conveyance upper guide 6. It receives frictional force and becomes conveyance resistance. Therefore, as shown in FIG. 4, the protrusion 5 is composed of a leaf spring, and the leaf spring 5 is bent so that it has a curl correction force, but on the other hand, it is bent by the tension of the roll paper winding. By selecting it, the transport resistance can be reduced. According to one embodiment of the present invention, the following effects can be obtained. 1. With a pair of protrusions and a notch with a simple structure provided on the conveyance guide, the curl at the tip of the roll paper is corrected,
The roll paper can be guided to the roll paper winding mechanism section. 2. By using a plurality of pairs of protrusions and notches, it is possible to cope with curling of wide roll paper. 3. By forming the protrusions with an elastic body, the curl at the leading end can be corrected by slightly increasing the roll paper conveyance resistance.

[0009]

Since the present invention is constructed as described above, the curl at the leading end of the roll paper is corrected by means of a simple structure provided on the conveying guide to roll the roll paper. The roll paper can be guided to the take-off mechanism.

[Brief description of drawings]

FIG. 1 is an overall schematic view of an embodiment of the present invention.

FIG. 2 is a perspective view of a portion showing the features of one embodiment of the present invention.

FIG. 3 is a diagram illustrating the operation of the present invention.

FIG. 4 is a diagram showing another embodiment of the present invention.

[Explanation of symbols]

 1 Roll Paper 2 Print Head 3 Platen 4 Transport Lower Guide 5 Protrusion 6 Transport Upper Guide 7 Roll Paper Winding Mechanism 8 Gate 9 Notch

Claims (1)

[Claims] 1. A method for carrying out a process such as printing on a roll paper, guiding the leading end of the roll paper to a gate at a specific position, and carrying a gap between the gate and the carrying path. A curl straightening mechanism at the leading end of the roll paper, characterized in that means for bending the roll paper in the width direction of the roll paper is provided at the trailing end of the roll paper transport guide.