JP3142147B2 - Printer paper feed mechanism - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a paper feed mechanism for a printer.

[0002]

2. Description of the Related Art As a paper feeding mechanism of a printer, generally, a type in which a recording sheet is conveyed while being nipped between a driving roller and a swing roller is often used. This type of paper feed mechanism has the advantage that the conveying force of the drive roller can be effectively transmitted to the recording paper, but on the other hand,
Depending on the processing accuracy and the assembling accuracy of these rollers, there is an inconvenience that the pressing force against the recording paper becomes uneven in the paper width direction and skew easily occurs.

[0003]

SUMMARY OF THE INVENTION The present invention has been made in view of such a problem.
It is an object of the present invention to provide a new paper feed mechanism for a printer that can minimize the occurrence of skew.

[0004]

That is, as a means for solving the above-mentioned problems, the present invention has a recording / writing section sandwiched between them.
To the recording paper from the paper load section provided on the upper side in the paper transport direction.
Applying tension to the lower side of the recording / writing section in the paper transport direction
The paper feed roller arranged to convey the paper and the urging member
In this state, the recording paper is nipped and transported in cooperation with this paper feed roller.
Paper feed mechanism of a printer equipped with a paper holding roller
Pressure of the paper press roller against the peripheral surface of the paper feed roller
A displacing means for displacing one of a paper feed roller and a paper holding roller in order to displace the paper feed roller back and forth with respect to a contact point of a paper transport path connecting the paper load section and the paper transport roller. It is.

[0005]

Embodiments of the present invention will be described below. 1 and 2 show a paper feed mechanism according to an embodiment of the present invention.

This paper feed mechanism is roughly classified into a recording / writing unit 40 for performing required recording / writing on the recording paper 1 and a recording / writing unit 40.
And a paper loading unit 50 provided on the upper side in the paper feeding direction to apply a constant tension to the recording paper 1.

The recording / writing unit 40 includes two guide shafts 6,
And a drive motor 11 for reciprocating the head carrier 8 coupled to a part thereof via the belt 5 in the main scanning direction. It is configured.

On the other hand, a paper load unit 50 provided on the upper side of the recording / writing unit 40 in the paper transport direction is for transporting the recording paper 1 while applying a constant tension to the paper feed unit 30. The paper load unit 50 is configured to press the paper guide auxiliary plate 3 against the paper guide 2 and apply a required pressing force to the recording paper 1 therebetween.

On the other hand, a paper feed section 30 provided on the lower side of the recording / writing section 40 in the paper transport direction is constituted by a paper feed roller 14 and a paper pressing roller 15 which presses against the peripheral surface of the paper feed roller 14. The paper feed roller 14 is configured to rotate by being driven by the paper feed motor 12 via a gear 13 fixed to the shaft end, and the paper press roller 15 is supported by one end of a paper press lever 16. This lever 1
The paper feed roller 14 is pressed against the peripheral surface of the paper feed roller 14 by the urging force of the paper press spring 19 acting on the other end of the paper feed roller 6.

Reference numeral 18 in the figure denotes an eccentric bearing with a handle 18b rotatably attached to the left and right frames (not shown). As shown in FIG. A shaft hole 18a for supporting the fulcrum shaft 17 of the paper holding lever 16 is provided on the shifted vertical line O, and by rotating this eccentric bearing 18, the swing center of the paper holding lever 16 is moved vertically and the paper Displaced back and forth in the transport direction, the press-contact position N of the paper press roller 15 pivotally supported at the end thereof is moved back and forth in the rotational direction with the contact S in contact with the paper transport path of the paper feed roller 14, in other words, It is configured such that it can be displaced back and forth in the transport direction.

In the device constructed as described above, the normal state shown by the solid line in FIG.
Is rotated so that the eccentric bearing 18 is positioned above the vertical line O, and a fulcrum shaft 17 having both ends supported by the shaft hole 18a.
Is positioned just above the center of the eccentric bearing 18 by a distance Δd, and the paper holding lever 16 is held at the position indicated by the solid line in FIG.

As a result, the paper press roller 15 pivotally supported by one end of the paper press lever 16 comes into contact with the paper transport path of the paper feed roller 14 under the biasing force of the paper press spring 19. The recording paper 1 is pressed against the contact point S so as to sandwich the recording paper 1, and a predetermined gap is formed between the recording paper 1 and the print head 9 in a state where a constant tension is applied to the recording paper 1 with the paper load unit 50. This is transported.

On the other hand, both rollers 1
If the recording paper 1 is bent to one side and a so-called skew phenomenon occurs without pressing the recording papers 1 and 4 uniformly in the paper width direction, as shown in FIG. The eccentric bearing 18 by the angle Q in the counterclockwise direction in the figure.
Rotate one.

Thus, the fulcrum shaft 17, which is eccentrically supported by Δd on the vertical line O of the eccentric bearing 18 via the shaft hole 18a, displaces the supported paper feed lever 16 downward in the paper transport direction. Paper press roller 15 supported at one end
Under the state of being urged by the paper feed spring 19, the pressure contact position N of the paper feed roller 14 on the lower side in the paper feed direction from the above-mentioned contact point S, in other words, on the lower side in the rotation direction of the paper feed roller 14 It is displaced to the pressure contact position N.

For this reason, the recording paper 1 comes into contact with the peripheral surface of the paper feed roller 14 over the length from the contact S to the pressure contact position N from the state of contact at the contact S, and the increased contact The paper is correctly conveyed without causing skew due to friction and with the path slightly changed as shown by the two-dot chain line.

Similarly, when the eccentric bearing 18 is rotated clockwise in the figure and the nip position of the paper holding roller 15 is displaced to the upper side in the rotation direction of the paper feed roller 14, the displaced nip position The recording paper 1 is brought into contact with the peripheral surface of the paper feed roller 14 over the length from the contact point S to the contact point S, and the increased frictional force enables the recording paper 1 to be conveyed in the correct direction. By slightly displacing the conveying path of the recording paper 1 downward in the figure, the gap between the recording paper 1 and the print head 9 can be adjusted at the same time.

The embodiment shown in FIG.
The eccentric shaft portions 17a are provided at both ends of a fulcrum shaft 17 for supporting the fulcrum shaft, and this portion is supported by a bearing provided on a frame (not shown) of the printer main body. Can be changed so as to change the pressure contact position between the paper pressing roller 15 and the paper feed roller 14 which are supported at one end of the paper pressing lever 16.

On the other hand, in the embodiment shown in FIG. 4, the eccentric bearing 18 for supporting the shaft of the paper feed roller 14 is rotatably mounted on a bearing provided on the printer body frame. 14 and paper holding roller 1
5 so as to be able to change the pressure contact position.

[0019]

As described above, according to the present invention, the recording
Disposed paper feed roller and the paper pressing roller downstream side of the writing unit
At the same time, the pressing position of the paper pressing roller against the peripheral surface of the paper feed roller is displaced in the paper transport direction with respect to the contact point between the paper feed roller and the paper transport path. the contact surface between the recording paper and the paper feed roller I'm to be changed
To increase the frictional contact force,
The required tension to the recording paper at
As well as uneven feed in the paper width direction
Eliminates skew and eliminates paper
By displacing the press roller to the upper side in the paper transport direction,
Larger platen gap for thicker recording paper
To be displaced to the lower side in the paper transport direction.
Allows the subtly adjust the conveying path of more paper.

[Brief description of the drawings]

FIG. 1 is a perspective view of an apparatus showing one embodiment of the present invention.

FIG. 2 is a side view showing a main part of the same device.

FIG. 3 is a perspective view of an apparatus showing another embodiment of the present invention.

FIG. 4 is a perspective view showing still another embodiment of the present invention.

[Explanation of symbols]

 8 Head carrier 14 Paper feed roller 15 Paper press roller 16 Paper press lever 17 Support shaft 18 Eccentric bearing 19 Paper press spring S Contact N Press-contact position

Claims (4)

(57) [Claims] 1. An upper side in a paper conveying direction across a recording / writing section.
While applying tension to the recording paper from the paper loading unit
A paper feed roller arranged to convey the recording / writing section to the lower side in the paper conveyance direction, and the paper feed roller urged by an urging member.
A paper press mechanism provided with a paper press roller for nipping and transporting the recording paper in cooperation with the paper feed roller, wherein the pressing position of the paper press roller against the peripheral surface of the paper feed roller is set in front of the paper load unit. Rubeku is displaced in the longitudinal direction of sheet transport relative to the contact of the paper transport path connecting the serial paper feed roller,
Change either the paper feed roller or the paper press roller.
A paper feeding mechanism for a printer, comprising a displacement means for moving the paper. 2. The paper feed mechanism of a printer according to claim 1, wherein an eccentric bearing for supporting a paper feed roller shaft is rotatably provided on the printer body as the displacement means. 3. A printer according to claim 1, wherein said displacing means supports a paper press roller at one end of said paper press lever and a fulcrum shaft for swingably supporting said paper press lever.
2. A paper feed mechanism for a printer according to claim 1, wherein said paper feed mechanism is supported by a rotatable eccentric bearing attached thereto. 4. A paper feeder for a printer according to claim 1, wherein eccentric portions are provided at both ends of said fulcrum shaft, and said fulcrum shaft is rotatably mounted on said printer body via said eccentric portions. mechanism.