JPH07137889A - Paper conveying mechanism - Google Patents

Abstract

PURPOSE:To properly correct an oblique feed in no relation to any kind of paper by pressing a point end part of the paper, supplied to a paper conveying mechanism from a paper feed mechanism, to notched surfaces of oblique feed correcting rollers, and correcting the oblique feed. CONSTITUTION:When paper P, positioned in the uppermost position of a paper feed cassette, is fed to a paper guide part 6 in a paper conveying mechanism by actuating a paper feed roller rotated, the paper P is conveyed until its point end part is positioned in upper surf aces of guide rollers 7, 8. Here are locked oblique feed correcting rollers 11, 12 in a position where notched surfaces 9A, 10A of each notched part thereof are placed at a right angle relating to a paper conveying direction. From this condition, the guide rollers 7, 8 are rotated in the paper conveying direction by a prescribed driving mechanism. According to the above, frictional force by own weight of the paper P is generated, and its point end part is pressed to the notched surfaces 9A, 10A of the notched parts 9, 10 of the oblique feed correcting rollers 11, 12. In this way, diagonally feeding the paper P is corrected.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a paper transport mechanism incorporated in a printer or the like, and more particularly to a paper transport mechanism suitable for preventing skew of the paper fed from the paper feed mechanism.

[0002]

2. Description of the Related Art Conventionally, as described in, for example, Japanese Utility Model Publication No. 3-30358, a pair of support shafts are set in a non-parallel state with respect to the width direction of a sheet sent from a sheet holder. The paper is nipped by the width-shifting rollers,
The pair of width-adjusting rollers are rotated to bring one side edge of the paper into contact with one side surface of the guide portion in the width direction while moving the paper in the width direction, thereby preventing skew of the paper. A paper transport mechanism for transporting paper has been proposed.

[0003]

However, in the above-described conventional sheet conveying mechanism, when the sheet sent out from the sheet holding section is straightened and conveyed, the sheet is always conveyed in the width direction. Since one side edge of the paper is brought into contact with one side surface of the guide in the width direction, an unreasonable force is easily applied in the width direction of the paper, and the type of paper such as soft paper There is a problem that the paper may pass over the side surface of the guide portion and deviate from the regular paper transport path, or the paper may be easily wrinkled.

[0004]

It is an object of the present invention to provide a sheet conveying mechanism which is capable of improving the above-mentioned disadvantages of the prior art and, in particular, accurately correcting the skew of the sheet regardless of the type of the sheet. That is the purpose.

[0005]

SUMMARY OF THE INVENTION According to the present invention, there is provided a paper guide portion for guiding the paper supplied from a paper supply portion, and a paper provided on the downstream side of the paper guide portion for conveying the paper guided by the paper guide portion. In a paper transport mechanism including a transport roller for moving the first guide roller that feeds the paper guided by the paper guide unit to the transport roller side, the first guide roller is rotatable between the paper guide unit and the transport roller. A second guide roller, which is equipped and sends the paper guided by the paper guide section to the transport roller side in cooperation with the first guide roller, has an outer peripheral surface which is an outer peripheral surface of the first guide roller. The first guide roller is intermittently rotatable in a direction opposite to the rotation direction of the first guide roller at a position where it can come into contact with the paper guide, and the paper guide is provided on a part of the outer peripheral surface of the second guide roller. It adopts a configuration that is formed parallel to the axis of rotation of the second guide roller cutouts for temporarily locking the leading edge of the sheet while permitting loading of the guided sheet by. This aims to achieve the above-mentioned object.

[0006]

According to the present invention, the paper guide portion guides the paper guided by the paper guide portion to a part of the outer peripheral surface of the second guide roller which cooperates with the first guide roller to send the paper to the conveying roller side. Since the cutout portion that allows the carried-in sheet to be carried in and temporarily locks the leading edge of the sheet is formed parallel to the rotation axis of the second guide roller, the sheet cannot be transferred as in the conventional case. Compared with the case of correcting the skew by contacting one side surface of the guide in the width direction, it is possible to correct the skew of the paper without applying excessive force to the paper. Regardless of the conventional method, it is possible to solve the conventional problems such as the paper running over the paper guide portion and wrinkling of the paper when correcting the skew of the paper. Further, since the second guide roller has both the function of correcting the skew of the sheet and the function of feeding the sheet to the transport roller side, a mechanism for correcting the skew of the sheet is separately incorporated in the sheet transport mechanism. Compared to the case, the number of parts can be reduced and the structure of the paper transport mechanism can be simplified.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which the paper feeding mechanism of the present invention is applied to a printing apparatus will be described below with reference to the drawings.

First, a schematic structure centering on the sheet conveying mechanism of the printing apparatus according to the present embodiment will be described with reference to FIG. 2. In FIG. 2, the sheet feeding mechanism 1 for feeding sheets one by one to the sheet conveying mechanism, 1 shows a sheet transport mechanism 2 that transports the sheets supplied from the sheet mechanism 1 to a printing mechanism (not shown) one by one.

The paper feed mechanism 1 is always in contact with the paper feed cassette 3 in which a large number of papers P are stored in a stacked state, and the uppermost paper P stored in the paper feed cassette 3 and the paper feed direction (opposite in the figure). A pair of paper feed rollers 4 that can be rotated clockwise)
It is configured to include and. When the paper is fed to the paper transport mechanism 2 by the paper feed mechanism 1, the pair of paper feed rollers 4
.. is rotated counterclockwise in the drawing by a predetermined drive mechanism, so that the paper P positioned at the top of the paper feed cassette 3 is sent to the paper transport mechanism 2 side. In this case, the paper P of the paper feed mechanism 1 is fed out by the predetermined rotation of the paper feed roller 4 until the leading end portion in the transport direction is positioned on the upper surfaces of the guide rollers 7 and 8 described later. Reference numeral 4A in the figure denotes the rotation axis of the paper feed roller 4.

The paper transport mechanism 2 supports the paper guide portion 6 that supports the lower surface of the paper P delivered from the paper feed mechanism 1, and the paper P that is on the leading end side of the paper guide portion 6 and that is supported by the paper guide portion 6. A pair of guide rollers 7 and 8 (see FIG. 1) provided on the lower surface side of the leading end portion and a pair of guide rollers 7 and 8 that can be brought into contact with each other and lock the leading end side of the paper P in the paper transport direction. A pair of skew correction rollers 11 and 12 (see FIG. 1) in which the cutouts 9 and 10 are formed respectively, and a pair of main transport rollers 13 provided on the downstream side of the guide rollers 7 and 8.
.. and a pair of driven rollers 14, which are provided in contact with the main transport roller 13 .. In the figure, reference numeral 7A is the rotation axis of the guide rollers 7 and 8, reference numeral 11A is the rotation axis of the skew feeding correction rollers 11 and 12, reference numeral 13A is the rotation axis of the main conveyance roller 13 ..., Reference numeral 14A is the driven roller 14 ... Shows the axis of rotation of.

Next, the structure of the essential parts of the sheet conveying mechanism of this embodiment will be described with reference to FIG. 1. A fan-shaped notch 9 is formed in the outer peripheral portion of the skew feeding correction roller 11. The notch 9 locks the leading edge of the sheet P at the sheet skew correcting position (position in FIG. 2) of the skew correcting roller 11 and is parallel to the rotation axis 11A of the skew correcting roller 11. The first notch surface 9A and the second notch surface 9B orthogonal to the first notch surface 9A are formed.

Similarly, a fan-shaped notch 10 is formed on the outer peripheral portion of the skew feeding roller 12, and the notch 10 is located at the sheet skew correcting position of the skew feeding roller 12. At the position (FIG. 2), the first cutout surface 10A and the first cutout surface 10A formed on the surface parallel to the rotation axis 11A of the skew correction roller 12 while locking the leading edge of the paper P are provided. And a second notch surface 10B that is orthogonal to. The skew correction rollers 11 and 12 are intermittently rotated counterclockwise in the drawing by a predetermined drive mechanism.

The skew correcting rollers 11 and 12 are arranged such that the leading edge of the sheet P sent out from the sheet feeding mechanism 1 is a guide roller 7.
Positions where the first cutout surfaces 9A, 10A of the cutouts 9, 10 are perpendicular to the leading edge of the paper until the upper surface of the paper 8 is reached and the skew of the paper P is corrected as described later. (See FIGS. 1 and 2). In this case, the first cutout surfaces 9A and 10A of the cutout portions 9 and 10 of the skew feeding correction rollers 11 and 12 are in a state in which the skew feeding of the paper sheet P is corrected when the leading edge of the paper sheet P abuts (paper sheet). The transport direction of P is set to be in a regular state.

The guide rollers 7 and 8 are driven by a predetermined driving mechanism (clockwise direction in the figure) by a predetermined drive mechanism when the leading end of the paper P sent from the paper feed mechanism 1 reaches the upper surface of the guide rollers 7 and 8. ) To be rotated. Along with this, a frictional force due to the weight of the paper P is generated,
The leading end of the sheet P is pressed against the first cutout surfaces 9A and 10A of the cutouts 9 and 10 of the skew feeding rollers 11 and 12. As a result, the skew of the paper P is corrected.

The skew feeding rollers 11 and 12 are adapted to be rotated counterclockwise in the figure by a predetermined driving mechanism when the skew feeding of the sheet P is corrected. Along with this, the skewed sheet P is sandwiched between the guide rollers 7 and 8 and the skew correction rollers 11 and 12, and is sandwiched between the main transport roller 13 and the driven roller 14. It is being sent. As a result, the main transport rollers 13 ... Are driven to rotate counterclockwise in the figure by a predetermined drive mechanism, and as a result, in cooperation with the driven rollers 14 that rotate clockwise in the figure. The paper P is conveyed to a printing mechanism (not shown).

In this case, after the sheet P of the sheet guide portion 6 is sent to the printing mechanism side by the main transport roller 13 ... And the driven roller 14 ...
Is rotated counterclockwise by a predetermined amount so that the first cutout surfaces 9A and 10A of the cutout portions 9 and 10 are at right angles to the paper transport direction of the next paper P (see FIGS. 1 and 2). Please refer to)) again.

Next, the operation of this embodiment constructed as described above will be described.

When the paper feed roller 5 of the paper feed mechanism 1 rotates and sends out the paper P located at the uppermost position of the paper feed cassette 3 to the paper guide portion 6 of the paper transport mechanism 2, the paper P has its leading end portion. Are conveyed until they are located on the upper surfaces of the guide rollers 7 and 8. At this time, the skew correction rollers 11 and 12 are locked at positions (see FIGS. 1 and 2) where the first cutout surfaces 9A and 10A of the cutout portions 9 and 10 are perpendicular to the sheet conveyance direction. Has been done.

When the leading end portion of the paper P delivered from the paper feed mechanism 1 to the paper transport mechanism 2 reaches the upper surface of the guide rollers 7, 8, the guide rollers 7, 8 are driven by a predetermined drive mechanism in the paper transport direction ( It is rotated clockwise). Along with this, a frictional force due to the weight of the paper P is generated,
The front end of the paper P is pressed against the first cutout surfaces 9A and 10A of the cutouts 9 and 10 of the skew feeding rollers 11 and 12. As a result, the skew of the paper P is corrected.

After that, the sheet P whose skew has been corrected is sandwiched between the guide rollers 7 and 8 and the skew correction rollers 11 and 12, and the main transport roller 13 and the driven roller 1 are held.
As a result of being fed between the main conveyance roller 13 ...
Indicates the paper P to be conveyed to a printing mechanism (not shown) in cooperation with the driven rollers 14.

As described above, according to this embodiment, the leading end portion of the sheet fed from the sheet feeding mechanism 1 to the sheet conveying mechanism 2 is cut into the first notch portions 9 and 10 of the skew feeding rollers 11 and 12. Since the structure is configured to press the notched surfaces 9A and 10A to correct the skew of the paper, as compared with the conventional case where the paper is brought into contact with one side surface in the width direction of the paper guide portion to prevent the skew. It is possible to accurately prevent the skew of the paper without applying an excessive force to the paper. As a result, regardless of the type of the paper, it is possible to solve the conventional problems such as the paper running over the paper guide portion and wrinkling of the paper when correcting the skew of the paper.

Further, according to this embodiment, the skew feeding correction rollers 11 and 12 also have a function of correcting skew of the sheet and a function of feeding the sheet to the main transport roller 13 and the driven roller 14 side. Therefore, the number of parts can be reduced and the structure of the paper transport mechanism can be simplified as compared with the case where a mechanism for correcting skew of the paper is separately incorporated in the paper transport mechanism.

In this case, in this embodiment, the leading end portion of the sheet P and the first cutout surfaces 9A of the cutout portions 9 and 10 of the skew feed correction rollers 11 and 12 are provided in the vicinity of the skew feed correction rollers 11 and 12.
In addition to providing a sensor that detects the contact state with 10A,
Based on the detection signal of the sensor, the leading end portion of the paper P is the first cutout surface 9 of the cutout portions 9 and 10 of the skew feeding rollers 11 and 12.
The skew correction rollers 11 and 12 are determined by determining whether they are in contact with the A and 10A (whether or not the skew of the sheet P has been corrected).
It is also possible to provide a control unit for controlling the rotation operation of the above and to control the rotation of the skew feeding correction rollers 11 and 12 intermittently by the control unit.

Further, in this embodiment, an example in which the paper transport mechanism is applied to the printing device (printer device) is given.
The present invention is not limited to the printing device, and can be applied to other devices such as a plotter device.

[0025]

As described above, according to the sheet conveying mechanism of the present invention, the second guide roller that feeds the sheet guided by the sheet guide portion to the conveying roller side in cooperation with the first guide roller. A structure is formed in a part of the outer peripheral surface of the sheet, in which a notch portion for allowing the sheet guided by the sheet guide portion to be carried in and temporarily locking the leading edge of the sheet is formed parallel to the second rotation axis. Therefore, for example, when the sheet guided by the sheet guide unit is skewed, the leading edge of the sheet is locked by the cutout portion of the second guide roller to correct the skewed sheet. Therefore, unlike the conventional case where the sheet is brought into contact with one side surface in the width direction of the sheet guide portion to correct the skew, in other words, the sheet is corrected by applying a force in a direction orthogonal to the sheet guide direction. Unlike the case where the paper is skewed, it is straightened along the guide direction of the paper. It is possible to solve the problem such as wrinkles.

Further, according to the paper transport mechanism of the present invention, the second guide roller has both the function of correcting the skew of the paper and the function of feeding the paper to the transport roller side. As compared with a case where a mechanism for correcting skewed sheets is separately incorporated, the number of parts can be reduced and the structure of the sheet transport mechanism can be simplified.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing a configuration of a main part of a paper transport mechanism in a present embodiment to which the present invention is applied.

FIG. 2 is an explanatory diagram showing a skew correction state of a sheet in this embodiment.

FIG. 3 is an explanatory diagram showing a conveyance state of skew-corrected paper in this embodiment.

[Explanation of symbols]

1 Paper Feeding Mechanism as Paper Feeding Section 2 Paper Conveying Mechanism 6 Paper Guide Section 7,8 Guide Roller as First Guide Roller 9,10 Cutout 9A First Cutout Surface as Paper Locking Surface 10A Paper Non-engagement Second cutout surface as stop surface 11, 12, skew correction roller as second guide roller 11A Rotation axis as rotation axis of second guide roller 13 Main transport roller as transport roller P Paper

Claims (2)

[Claims] 1. A sheet having a sheet guide section for guiding the sheet supplied from the sheet supply section, and a conveyance roller provided downstream of the sheet guide section for conveying the sheet guided by the sheet guide section. In the transport mechanism, a first guide roller that feeds the paper guided by the paper guide unit to the transport roller side is rotatably provided between the paper guide unit and the transport roller, and the paper guide unit A second sheet for feeding the guided sheet to the conveying roller side in cooperation with the first guide roller.
The guide roller is provided at a position where the outer peripheral surface of the guide roller can contact the outer peripheral surface of the first guide roller, and is intermittently rotatable in a direction opposite to the rotation direction of the first guide roller. The second guide roller is provided with a cutout portion at a part of the outer peripheral surface thereof, the cutout portion allowing the sheet guided by the sheet guide portion to be carried in and temporarily locking the leading edge of the sheet.
A sheet conveying mechanism, which is formed in parallel with the rotation axis of the guide roller. 2. The cutout portion is parallel to the rotation axis of the second guide roller and is substantially orthogonal to the flat paper locking surface for locking the leading edge of the paper. The sheet transport mechanism according to claim 1, wherein the sheet transport mechanism is formed by a flat sheet non-locking surface.