JPH06155837A - Printer - Google Patents

Abstract

PURPOSE:To print in high quality by conveying a sheet in a predetermined sheet conveying direction irrespective of thickness of the sheet. CONSTITUTION:The printer comprises sheet pressing position regulating means 30 so moving a support shaft 12 of a sheet retaining member 11 in A sheet conveying direction as to bring sheet pressing position (X1, X2) of the member 11 into coincidence with a reference pressing position Xs.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a printing device such as an ink jet printer.

[0002]

2. Description of the Related Art FIGS. 4 to 6 show a schematic structure of a conventional ink jet printer. In these drawings, 1 is a main body frame, which is a print head (inkjet head 2),
The carrier 3, the head position adjusting means 5, the feed roller 8, the sheet pressing member 11 and the like are housed.

The feed roller 8 is rotatably supported between both sides 1L and 1R of the main body frame 1 via a shaft 8a, and is rotated clockwise by a drive mechanism (not shown) in FIG. It is provided so that it can be urged to feed on the paper transport guide 9 toward F. The inkjet head 2 is mounted on a carrier 3 and is configured to be movable between both side portions 1L and 1R of the main body frame 1 via a carrier shaft 4 (axial center C3).

The head position adjusting means 5 is for adjusting the height position of the paper feed guide 9 of the ink jet head 2 with respect to the carrying surface 9a, and each end of the carrier shaft 4 (axis C3) is attached to the main body frame 1. Each side 1L, 1R
Eccentric bushes 6 and 6 eccentrically supported (axial center C4)
And a lever 7 for rotating the eccentric bush 6. When the eccentric bushes 6 and 6 are rotated using the lever 7, the carrier shaft 4 is eccentrically moved and the inkjet head 2 approaches (or is separated from) the paper transport guide 9. Accordingly, the position of the head 2 can be adjusted by appropriately rotating the lever 7.

The paper pressing member 11 is rotatably supported by the main body frame 1 via the support shaft 12 upstream of the ink jet head 2 in the paper conveying direction and presses the paper against the feed roller 8 by the elastic force of the paper pressing spring 13. Is.

Therefore, the paper (thin paper P1) fed between the feed roller 8 and the paper pressing member 11 is pressed by the paper pressing member 11 against the feed roller 8 and is tangential to the peripheral surface of the feed roller 7 at the pressing position X1. The paper (P1) is conveyed toward the head 2 on the conveyance surface 9a of the paper conveyance guide 9 by being urged to be fed in the direction (paper conveyance direction).

[0007]

In the ink jet printer described above, when the paper is thick paper P2 like an envelope, the paper pressing member 11 presses the paper (P2) due to the difference in thickness from the thin paper P1. As shown in FIG. 6, the moving position is slightly shifted upstream in the paper transport direction. Therefore, the feeding biasing direction of the paper (thick paper P2) by the feed roller 8 is changed to the ink jet head 2 side, and the paper (P
2) is conveyed toward the head 2 in a state of being lifted from the sheet conveyance guide 9. Therefore, the paper (P
2) may rub against the head 2 to cause ink stains or paper jams.

SUMMARY OF THE INVENTION In view of the above circumstances, an object of the present invention is to provide a printing apparatus which can carry out high quality printing by carrying a paper in a constant paper carrying direction regardless of the thickness.

[0009]

SUMMARY OF THE INVENTION A printer according to the present invention comprises a feed roller capable of feeding and biasing a sheet toward a print head on a sheet conveying surface, and a support shaft upstream of the print head in the sheet conveying direction. In a printing device provided with a paper pressing member that is rotatably disposed and can press a paper against a feed roller, a support shaft of the paper pressing member so that the paper pressing position of the paper pressing member matches a reference pressing position. Is provided with a paper pressing position adjusting means that is movable in the paper transport direction.

[0010]

According to the present invention having the above-described structure, when printing sheets of different thickness, the support shaft of the sheet pressing member is appropriately moved in the sheet conveying direction by using the sheet pressing position adjusting means to move the pressing member. Match the paper pressing position with the reference pressing position. As a result, the paper is conveyed in a fixed paper conveyance direction, and it is possible to prevent the paper from approaching the print head excessively. Therefore, it is possible to prevent the paper from coming into contact with the print head to be contaminated with ink and to cause a paper jam. Therefore, it is possible to carry out high-quality printing by carrying the paper in a fixed paper carrying direction regardless of the thickness.

[0011]

Embodiments of the present invention will be described below with reference to the drawings. This printing apparatus is of an ink jet type, and has a basic configuration (main body frame 1, ink jet head 2, carrier 3, head position adjusting means 5, feed roller 8, paper pressing member 11, etc.) as shown in FIG. (Fig. 6)
And the paper pressing position of the paper pressing member 11 (X
1, X2) is provided with a paper pressing position adjusting means 20 capable of moving the support shaft 12 of the paper pressing member 11 in the paper transporting direction so as to match the reference pressing position Xs.
The paper can be conveyed in a constant paper conveyance direction regardless of the thickness. In this printing apparatus, the paper pressing position X1 of the thin paper P1 is selected as the reference pressing position Xs. The same or common components as those of the conventional example (FIGS. 4 to 6) are designated by the same reference numerals, and the description thereof will be simplified or omitted.

Here, the paper pressing position adjusting means 20 is configured to be operated in conjunction with the head position adjusting means 5 in order to reduce the number of parts. Specifically, the paper pressing position adjusting means 20 is interlocked with the rotation operation of the lever 7 of the head position adjusting means 5, and the support shaft 1 of the paper pressing member 11 is supported.
Eccentric bush 2 with gear that moves 2 in the paper transport direction
It is configured to include 1 and 22.

In this embodiment, the support shaft 12 (axial center C2) is supported at both ends by the eccentric bushes 21 and 21 (axial center C1) on both sides 1L and 1R of the main body frame 1. A gear portion 21a is integrally formed with the eccentric bush 21. Further, the eccentric bushes 22 and 22 connect both end portions of the carrier shaft 4 to both side portions 1L and 1L of the main body frame 1.
It is eccentrically supported by R (axis C4), and the bushes 22 and 22 are provided with gear portions 22a and 22a.
It is integrally formed so as to mesh with a and 21a.
Therefore, when the eccentric bush 22 is rotated counterclockwise in FIG. 1 when the thick paper P2 is printed as the paper by using the lever 7, the carrier shaft 4 is eccentrically moved as shown in FIG. The position with respect to the paper transport guide 9 is adjusted. Further, as the eccentric bush 21 rotates, the eccentric bush 21 on the side of the sheet pressing member 11 is rotated clockwise in FIG. 1 by an angle amount corresponding to the number of teeth of each gear portion 21a, 22a, and the spindle is rotated. 12 is lifted upward along the paper transport direction. As a result, in the paper pressing member 11, the paper pressing position X2 is changed to the reference pressing position Xs.
It is positioned and held at a position matching with.

Similarly, when the lever 7 is positioned at the position shown in FIG. 1 in order to print the thin paper P1 as the paper, the paper pressing member 11 causes the eccentric bushes 21 and 22 and the support shaft 12 to move.
The sheet pressing position X1 is moved to the reference sheet pressing position Xs by moving in the sheet conveying direction via. That is, in the present embodiment, the paper pressing position X of the thin paper P1 is set as the reference pressing position Xs.
1 is selected.

Next, the operation of this embodiment will be described.
When printing various papers (P1, P2) having different thicknesses, the lever 7 is used according to the thickness of the papers (P1, P2).
When the head position is adjusted by using, the paper pressing position adjusting means 20 is actuated to move the paper pressing member 11 in the paper conveying direction to move the paper pressing positions (X1, X2) to the reference pressing position X.
match s. As a result, the paper (P1, P2) is
Since the paper is conveyed in a fixed paper conveyance direction, it is possible to prevent the paper (P1, P2) from approaching the inkjet head 2 excessively. Therefore, the paper (P
1, P2) are prevented from coming into contact with the print head 2 to cause ink stains and paper jams.

However, according to this embodiment, the support shaft 12 is movable in the paper transport direction so that the paper pressing position (X1, X2) of the paper pressing member 11 coincides with the reference pressing position Xs. Since the adjusting means 20 is provided, it is possible to prevent the paper (P1, P2) from coming into contact with the inkjet head 2 and stain the ink, thereby improving the print quality.

Further, since the paper pressing position adjusting means 20 is configured to operate in conjunction with the head position adjusting means 5, it is possible to reduce the number of parts, improve the handleability, simplify the structure, and reduce the cost. Can be achieved.

[0018]

According to the present invention, the paper pressing position adjusting means is provided which is capable of moving the support shaft of the paper pressing member in the paper conveying direction so that the paper pressing position of the paper pressing member coincides with the reference pressing position. Since the configuration is adopted, the paper can be conveyed in a constant paper conveyance direction regardless of the size of the thickness and high-quality printing can be performed.

[Brief description of drawings]

FIG. 1 is a diagram for explaining an essential part of an embodiment of the present invention.

FIG. 2 is a diagram showing how thick paper is printed in the same manner.

FIG. 3 is likewise a diagram for explaining the overall configuration.

FIG. 4 is a perspective view for explaining the overall configuration of a conventional inkjet printer.

FIG. 5 is a diagram showing how thin paper is printed by a conventional inkjet printer.

FIG. 6 is a diagram showing how thick paper such as an envelope is printed by a conventional inkjet printer.

[Explanation of symbols]

 2 Inkjet head 8 Feed roller 11 Paper pressing member 12 Spindle 21 Paper pressing position adjusting means

Claims (1)

[Claims] 1. A feed roller capable of urging and feeding a sheet toward a print head on a sheet conveying surface, and a feed roller rotatably arranged upstream of the print head in the sheet conveying direction via a support shaft. In a printing device having a paper pressing member that can be pressed to a paper pressing position, the support shaft of the paper pressing member can be moved in the paper transport direction so that the paper pressing position of the paper pressing member matches the reference pressing position. A printing device comprising means.