JPS60106760A - Paper feeder - Google Patents

Abstract

PURPOSE:To provide predetermined tensile force even when the winding diameter of a feeding roll has reduced and enable paper feeding with high accuracy by increasing the sliding resistance between said feeding roll and a braking surface, which slides on its outer periphery in accordance with the winding diameter of said feeding roll consisting of a roll of paper. CONSTITUTION:In a paper feeder for a printer, etc., a roll of record paper 21 is wound on a feeding roll 22 and is transferred, being drawn out by a capstan roller 23 and a pinch roller 24. On the inner surface of a roll of paper feeding case 25, braking surfaces 25A, 25B, which are brought in contact with the outer periphery of the feeding roll 22, are formed. As the winding diameter of the feeding roll 22 is reduced, as shown by the dotted lines 22A, 22B. The feeding roll 22 is gradually fitted into a gap formed by the braking surfaces 25A, 25B, gradually increasing the sliding resistance. Thereby the tensile force, on drawing out the roll of record paper 21, can be maintained nearly constant, carrying out paper feeding with high accuracy.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a paper feeding device for a printer or the like that uses roll paper as recording paper.

2. Description of the Related Art Structures of Conventional Examples and Their Problems In recent years, with the spread of personal computers and word processors, the demand for printers, which are their output devices, has increased. The types of recording paper used in printers are broadly divided into cut paper, which is cut into a regular shape in advance, fan-fold paper, which is a continuous sheet of paper that is folded, and roll paper, which is a continuous sheet of paper that is wound. Each type of recording paper is used differently depending on its purpose and device.

Below, problems with conventional roll paper feeding devices will be explained using a thermal transfer recording type color printer as an example. FIG. 1 is a side view of a conventional paper feeding device, in which numeral 1 denotes a thermal head, here a line head, which is movable at a position indicated by a dotted line 1A. 2 is an ink sheet for thermal transfer recording, 3 is a take-up roll for the ink sheet 2, 4 is a supply roll for the ink sheet 2, 5 is a recording paper, 6 is a supply roll for the recording paper 5, and 7 is a supply roll 6. In the receiving roll paper supply box,
fixed to the device. A platen roller 8 brings the ink sheet 2 and the recording paper 5 into close contact with each other and presses them against the thermal head 1, and a rubber material is molded around the outer periphery of the platen roller. 9 is a pressure roller that presses the recording paper 5 against the platen roller 8; 10;
1 is a capstan roller that transports the recording paper 6, and 11 is a pinch roller that presses the recording paper 5 against the capstan roller 10.

Next, the operation of the conventional device configured as described above will be explained. The principle of a thermal transfer recording type color printer is simple; as shown in Figure 1, an ink sheet 2 and recording paper 5 are brought into close contact with each other and pressed against a thermal head 1, and the heat-generating ink sheet 2 of the thermal head 1 is heated. Then, the ink applied to the ink sheet 2 is melted and transferred to the recording paper 5. On the ink sheet 2, yellow, magenta, and cyan color inks are sequentially applied to different parts, and are sequentially superimposed and transferred onto the recording part of the recording paper 5. Since the ink sheet 2 is transported only in one direction shown by arrow A, the recording paper 5 is returned to its original position each time each color is transferred. This reciprocal transport of the recording paper 6 is performed by a capstan roller 1° and a pinch roller 11. The platen roller 8 follows the recording paper 5 in the direction of arrow B (recording direction), and is lightly driven so as to be able to slip in order to carry out the recording paper 5 in the direction of arrow C (return direction). When transferring in the direction of arrow C, the thermal head 1
is moved to the position indicated by the dotted line 1A, so that only the recording paper 5 can be transported.

In the above-described printing apparatus, alignment between the previously recorded color and the subsequently recorded color is an important issue, and this positional deviation is particularly referred to as color blurring. Most of the causes of color shift are due to the reproducibility of the position when the recording paper 5 is returned to its original position and recorded again. One of the key factors in improving this reproducibility is the feeding spoon for the recording paper. In other words, in the conventional example, at the start of recording, the operation of first conveying the recording paper 5 in the direction of arrow C by the recording length is as follows.
Necessary for paper feeding operation. At this time, the direction of the recording paper 5 from the capstan roller 1o to the pressure roller 9-1 needs to match the direction of transport of the capstan roller 10 and the pinch roller 11 with high precision. This is because if the two directions do not match and the recording paper 5 is fed diagonally, while the recording paper 6 is being transported back and forth by the capstan roller 1o and the pinch roller 11,
This is because the recording paper 5 may be misaligned (misaligned in the width direction), causing color misregistration. To avoid this, conventional efforts have been made to increase the positional accuracy of the roll paper supply box a and to improve the parallelism between the supply roll 6 and the capstan 1o. At the same time, the recording paper 6 is stretched by the sliding resistance (sliding friction force) between the outer periphery of the supply roll 6 and the inner surface of the roll paper supply box 7, and the position and direction of the recording paper 6 on the capstan 10 is The aim was to regulate or correct the However, as shown in the 21st line 1, the tension of the recording paper 5 pulled out from the supply roll 6 decreases as the winding diameter decreases. This is because the weight of the supply roll 6 decreases, and if the roll diameter becomes smaller as a result, the position and direction of the recording paper 5 is difficult to be regulated or corrected in the capstan 10 during paper feeding, making it unstable. become. As a result, there is a problem in that lateral deviation and color deviation of the recording paper 6 are likely to occur, making it difficult to solve the problem of feeding roll paper with high precision without lateral deviation using a simple configuration.

Purpose of the Invention The present invention solves the above-mentioned conventional problems, and provides a paper feeding device that allows paper feeding without lateral deviation with a simple configuration even when the winding diameter of the supply roll becomes small. The purpose is to provide.

Structure of the Invention The present invention is a paper feeding device equipped with a braking surface that increases sliding resistance with the supply roll as the winding diameter of the supply roll decreases. Even when the tension is lowered, a predetermined tension can be applied to feed the paper with high precision.

DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments of the present invention will be described. FIG. 3 is a side view of a paper feeding device according to an embodiment of the present invention, which is used in a recording device as shown in the conventional example. In 1, 21 is a recording paper, 22 is a supply roll for the recording paper 21, 23 is a capstan roller that pulls out and transports the recording paper 21, 24 is a pinch roller molded with rubber material,
25 is a roll paper supply box. The roll paper supply box 25 has a braking surface 258 on its inner surface that contacts the outer periphery of the supply roll 22.

25B, and not only processes the sliding resistance +a when the supply roll 220 rotates, but also positions the supply roll 22. 25C is the width direction regulating surface.

In this embodiment, as the winding diameter of the supply roll 22 decreases and becomes smaller as indicated by dotted lines 22A and 22B, the supply roll 22 fits into the gap formed by the braking surfaces 25A and 25B. Sliding resistance increases.

Therefore, the tension when drawing out the recording paper 21 can be kept relatively constant regardless of changes in the winding diameter. As a result, even when the winding diameter is small, the supply rolls 22A, 2
2B, the recording paper 21 is stretched between the capstan roller 23, and the position or direction in the width direction can be regulated and corrected.

In this embodiment, the braking surfaces 25A and 25B may be uniform surfaces made of the same material, and can be easily molded.

FIG. 4 is a side view of a paper feeding device according to another embodiment of the present invention, which is used in a recording device as shown in the conventional example. In the figure, 31 is recording paper, 32 is recording paper 3
1 supply roll; 33, a capstan roller that pulls out and transports the recording paper 31; 34, a pinch roller molded with rubber material;
to press. A roll paper supply box 35 receives the supply roll 32. The roll paper supply box 35 has braking surfaces 35A and 35B on its inner surface that contact the outer periphery of the supply roll 32, and applies sliding resistance when the supply roll 32 rotates.
The supply roll 32 is also positioned. 35C is a widthwise regulating surface, which regulates lateral displacement of the supply roll 32. 3
6.37 is a sliding resistance increasing plate, which is made by pasting a rubber sheet or chamois leather, etc.
The coefficient of friction with the outer periphery of the braking surfaces 35A and 35B is made higher than that of the braking surfaces 35A and 35B. 38.39 is also a sliding resistance increasing plate,
It is made by pasting a rubber sheet or the like, and the coefficient of friction with the outer periphery of the supply roll 32 is selected to be higher than that of the sliding resistance increasing plates 36 and 37.

Now, in the above-mentioned other embodiment, as the winding diameter of the supply roll 32 decreases and becomes smaller as indicated by the dotted lines 32A and 32B, the outer periphery changes to the sliding resistance increasing plates 36, 37, and 38.
．． 39, and the sliding resistance increases step by step. Therefore, the tension when drawing out the recording paper 31 can be kept relatively constant regardless of changes in the winding diameter. As a result, even when the winding diameter is small, the supply rolls 32A, 32B
It is possible to securely position the recording paper 31 between the capstan roller 33 and transport the recording paper 31 under tension, thereby regulating and correcting the position or direction in the width direction. The present invention can also be implemented by applying another embodiment shown in FIG. 4 to the embodiment shown in FIG. 3 to change the sliding resistance of the braking surface. By combining multiple materials like ゜37, 38, 39, it becomes easier to change the sliding resistance.

Effects of the Invention As described above, the paper feeding device of the present invention provides a braking surface that increases the sliding resistance with respect to the outer periphery of the supply roll as the winding diameter of the supply roll decreases. Even when the roll diameter becomes small, a predetermined tension can be applied and paper can be fed with high precision. In particular, the present invention has the advantage that there is no need to pass a shaft through the supply roll and hold it, which simplifies the operation of replacing the supply roll and the structure of the device.
Its practical effect is great 0

[Brief explanation of the drawing]

FIG. 1 is a side view of a recording apparatus equipped with a conventional paper feeding device, FIG. 2 is a characteristic diagram showing the tension characteristics of the roll paper drawer of the conventional paper feeding device, and FIG. 3 is an embodiment of the present invention. FIG. 4 is a side view of the paper feeding device in another embodiment. 23.33... Capstan roller, 24.34
...Pinch roller, 25, 35 ... Roll paper supply box, 25A, 25B ... Braking surface,
36,37゜38.39...Sliding resistance increasing plate. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 1
Figure 2: Xianggaru Figure 3: Figure 4

Claims (1)

[Scope of Claims] (1) A supply roll formed by winding a strip of paper, a transfer means for drawing out the paper from the supply roll, and a braking surface that slides on the outer periphery of the supply roll when the paper is drawn out. A paper feeding device comprising: a paper feeding device that increases sliding resistance between the supply roll and the braking surface in accordance with a decrease in the winding diameter of the supply roll; (2) providing at least two braking surfaces that slide on the outer periphery of the supply roll; , the paper feeding device according to claim 1, wherein the angle formed by the braking surface is changed according to the sliding position. Paper feeding device according to scope 1.