JP3525028B2 - Paper feeder - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a paper feeding device used in a printer.

[0002]

2. Description of the Related Art Providing a stack of recording sheets below a recording / writing section is a good measure for reducing the space for arranging the apparatus. Since the paper must be formed in a U shape, when the paper is thick, there is a difference in the feed amount, and in the case of overlapping sheets such as labels and envelopes, the inside paper and the outside Lifting occurs due to the difference in the curvature of the paper, and in the case of strong paper, the back tension
Down it takes a result, exert not a little adverse effect on the print quality is poor feeding accuracy of the recording paper.

[0003]

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and its object is to:
It is an object of the present invention to provide a new paper feeding device capable of feeding a recording paper to a recording / writing unit with high accuracy through a paper feeding path having a large curvature regardless of the paper type.

[0004]

That is, the present invention is, as a paper feeding device for achieving such a problem, a flat paper feeding path provided with a first paper feeding roller for feeding a recording paper to a recording / writing section. , the second paper feed roller and two pressing rollers for pressing the <br/> recording sheet to the peripheral surface of the second paper feed roller for conveying the stack unit reverses the recording paper into the paper transportation path And the paper feed operation of the first paper feed roller
In synchronism with, and the recording sheet by the first sheet feed roller
And a cam member that displaces the two pressing rollers in the non-pressing direction during conveyance .

[0005]

With this configuration, the pressing roller is displaced in the non-pressing direction in synchronization with the paper feeding operation of the first paper feeding roller, and the back tenn of the recording paper on the reversing paper conveyance path is > by reducing the sucrose down, in which so as to improve the paper feeding accuracy of the first sheet feed roller.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below. Each of the drawings shows an embodiment of the present invention.

In the printer body indicated by reference numeral 1 in the drawing, a sub paper feed roller 2 as a second paper feed roller is sandwiched, and a recording paper in a hopper 3 is directed below the sub paper feed roller 2 toward the sub paper feed roller 2. pickup roller 5 is arranged to feed, also, in its upper, as a first paper feed roller, and a flat paper guide 20 which includes a paper feed roller 21 of the main is provided, the sub-paper feeding roller The recording paper, which has been inverted and conveyed in a U-shape by 2, is fed directly below the inkjet recording head 24.

By the way, reference numerals 7, 7 and 13 are first and second pressing rollers arranged around the sub paper feeding roller 2, and these pressing rollers 7 and 13 feed the recording paper mainly. When it is fed to the roller 21, it is operated by a cam 18 described later so as to be separated from the peripheral surface of the sub paper feed roller 2.

The first of these pressing rollers 7, 13
The pressing rollers 7, 7 are supported by a common supporting frame 8 and are arranged on the lower side in the paper transport direction of the hopper 3 through the paper edge detection sensor 6, and the supporting frame 8 is swingable. A cam 1 which is connected to the tip of a pivotally supported first roller release lever 9 via a pressing rod 10 having a D-shaped cross section and acts on this lever 9.
8, when it is operated by the pressure roller 7,
7 operates so as to be separated from the peripheral surface of the sub paper feed roller 2, but is normally urged by the urging spring 11 to press the pressure rollers 7 and 7 against the peripheral surface of the sub paper feed roller 2. .

On the other hand, the second pressing roller 13 is supported by the second roller release lever 14 and near the confluence of the flat paper guide plate 20 and the manual guide plate 22.
The sub paper feed roller 2 is disposed in the sub paper feed roller 2, and is normally pressed against the peripheral surface of the sub paper feed roller 2 by the biasing spring 15 acting on the lever 14. However, the recording paper is the main paper feed roller 21. When the paper is sent to the original or when the manual paper is sent in, the roller release lever 1
It is configured to be separated from the surface of the sub paper feed roller 2 by a cam 18 that acts on the roller 16 at the four ends.

On the other hand, the cam 18 is supported by the shaft 17 of the sub paper feed roller 2 and is driven by a paper feed motor (not shown) to repeat forward rotation and reverse rotation, while pressing each of these pressure rollers 7 and 13 to the sub paper. It can be separated from the peripheral surface of the feed roller 2,
They are pressed against each other.

In the figure, reference numeral 4 is a pad for preventing multi-sheet feeding provided at the tip of the hopper 3, 25 is a sensor for detecting a cue provided immediately before the main paper feed roller 21, and 27 is a series of ejections. Each pair of paper rollers is shown.

In the paper feeding device thus constructed, when a signal for paper feeding is inputted, the cam 18 driven by the paper feeding motor rotates in the direction of the arrow in FIG. 1 to release the first roller release. Release the push-up of the lever 9 and the support frame 8
By the biasing spring 11 acting on the two pressing rollers 7,
7 is evenly pressed against the peripheral surface of the sub paper feed roller, and the pushing up of the second roller release lever 14 is released, and the pressing roller 13 on this lever 14 is moved by the urging force of the spring 15 to cause the sub paper feed roller 2 to move. Press on the peripheral surface.

Therefore, when the pickup roller 5 next starts to rotate counterclockwise in this state, the recording paper pulled out from the hopper 3 by this roller 5 becomes
It reaches the sub paper feed roller 2 through the multi-sheet feed prevention pad 4 and the paper edge detection sensor 6 and is reversed and conveyed while being pressed by the pressure rollers 7 and 7, and passes between the second pressure rollers 13. And is delivered onto a flat paper guide plate 20.

When the recording paper is fed to the main paper feed roller 21 in this way, the cue detection sensor 25 arranged immediately before it detects the recording paper and the sub paper feed is performed by the detection signal. At the same time when the driving force to the roller 2 is cut off, as shown in FIG. 2, the planet mechanism (not shown) is reversed to rotate the first roller release lever 9 counterclockwise in the figure by the crest 18a of the cam 18. and evaporated to separate the two pressing rollers 7 and 7 journalled to support frame 8 from the peripheral surface of the sub-paper feeding roller 2, also in the clockwise the second roller release lever 14 by the ridges 18 b of the cam 18 The pressing roller 13 on the lever 14 is separated from the peripheral surface of the sub paper feed roller 2 by rotating in the direction. Further, for transmitting the driving force between the sub paper feed roller 2 and the driving means such as a driving motor.
The connection of is released by a means such as a planetary lever or a one-way clutch.

As a result, the sub paper feed roller 2 can freely roll, and the recording paper wound on the sub paper feed roller 2 is released from the pressing by the first and second pressing rollers 7 and 13, so that the main The paper feed roller 21 is a sub paper feed roller 2
Without being affected by the above, the feeding amount of the recording paper is fed to the recording head 24 while the feeding amount of the recording paper is controlled correctly on the flat paper feeding path 20, and clear characters are printed on the surface regardless of the paper quality. , Draw a figure.

When printing on a manual paper such as a postcard, the paper is fed between the sub paper feed roller 2 and the second pressing roller 13. As a result, a detection sensor (not shown) that has detected this manual feed paper operates the sub paper feed roller 2 in accordance with the detection signal to feed it to the main paper feed roller 21, and then the second pressure roller 1
3 is separated from the sub paper feed roller 2 and printing is performed. In this embodiment, since there is no difference in the curvature of the paper between the manual feed path and the automatic paper feed path, the same pitch accuracy can be obtained.

[0018]

As described above, according to the present invention , the first
After feeding the recording paper to the paper feeding roller of No. 2, by releasing the restraint of the recording paper on the second paper feeding roller,
The influence of the tension of the recording paper on the first paper feed roller or the load accompanying the conveyance of the recording paper can be reduced, the difference in the feed amount depending on the paper type can be eliminated, and at the same time, the recording paper to the recording / writing unit can be changed. The feeding accuracy can be improved.

Further, by interrupting the driving force transmission to the second paper feed roller in synchronism with the operation of the first paper feed roller, the load accompanying the feeding of the recording paper can be further reduced, and the recording / writing unit the feeding accuracy of the recording paper makes it possible high Mel to, by disposing a pressing roller in the vicinity confluence of the manual feed path, it is possible to allow also the paper feeding by manual insertion, and by the route The difference in paper feed amount can be eliminated.

[Brief description of drawings]

FIG. 1 is a configuration diagram of an apparatus according to an exemplary embodiment of the present invention, which is shown in a feeding state.

FIG. 2 is a configuration diagram of the same apparatus shown in a printed state.

[Explanation of symbols]

2 Sub paper feed roller 3 hoppers 7, 7, 13 Pressing roller 18 cams 20 Flat paper transport path 21 Main paper transport roller 22 Bypass route 24 recording head

─────────────────────────────────────────────────── ─── Continuation of the front page (56) Reference JP-A-7-149012 (JP, A) JP-A-7-309501 (JP, A) JP-A-3-36152 (JP, A) JP-A-7- 33279 (JP, A) JP 7-329380 (JP, A) Actual development Sho 59-173638 (JP, U) (58) Fields investigated (Int.Cl. ⁷ , DB name) B65H 5/06 B41J 13 / 00

Claims (3)

(57) [Claims] 1. A flat paper conveyance path having a first paper feed roller for feeding the recording paper to the recording / writing section, and a second conveyance means for inverting and conveying the recording paper from the stack section to the paper conveyance path.
A paper feed roller, the recording sheet in synchronism with the paper feed operation of the two pressing rollers for pressing the circumferential surface of the second sheet feed roller, the first paper feed roller, and said first sheet Sending
And a cam member that displaces the two pressing rollers in the non-pressing direction while the recording paper is being conveyed by the roller . 2. The paper according to claim 1, further comprising means for disconnecting the connection between the second paper feed roller and the drive source in synchronism with the paper feed operation of the first paper feed roller. Feeder. Wherein said flat manual feed paper path is arranged on the hand side of the paper conveyance path, we were provided with one of the two pressing rollers near confluence between the flat sheet conveying path and manual sheet feed path The paper feeding device according to claim 1, wherein