JPH11227291A - Paper feeder in printer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a printer for enhancing print quality. SOLUTION: The paper feeder comprises a member 13 for guiding a received print fed P along a platen 12, a mechanism B for adjusting the gap of paper passage with respect to the platen 12, and a mechanism A for adjusting the gap between the platen 12 and a print head 1. Adjustment of paper passage gap and adjustment of platen gap are interlocked through action of a single operating lever 17. Since the paper passage gap can be adjusted optimally when the platen gap is adjusted, flexure of sheet can be suppressed and high print quality can be ensured.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an impact type printer using a printing member such as a wire.
In particular, the present invention relates to a paper feeding device in a printer capable of improving print quality.

[0002]

2. Description of the Related Art Generally, in an impact type printer having a printing member such as a wire or a printing bar,
By printing (printing) a printing ribbon and a printing paper, which are arranged on top of each other on a platen, with a printing member, the ink impregnated in the printing ribbon is transferred onto the printing paper to perform printing. .

In this type of printer, a tractor and / or a paper feed roller for feeding print paper to a print area by a print head is provided. After being printed by the head, the paper is discharged by a paper discharge roller.

FIG. 5 is a sectional view showing a main part of a conventional printer of this type. That is, a print head 53 fixed to the carriage 52 is disposed so as to face the platen 51 formed in a cylindrical shape, and the print head 53 moves along a guide shaft 54 disposed in parallel with the longitudinal direction of the platen 51. It is configured to be able to move.

[0005] Printing paper P, such as continuous slip paper, is fed by a pair of tractors (not shown) arranged at a front position in the paper transport path, and a gap between the paper guide member 55 and the platen 51 is formed. Print head 5 through
3 on the movement trajectory. Then, the printing paper P printed by the print head 53 at the position is discharged by the discharge rollers 5.
6 and a pressure roller 57 opposed thereto, so as to be fed to the upper rear of the printer.

A guide shaft 54 supporting the carriage 52 on which the print head 53 is mounted has a guide shaft 5
A support shaft 54a is integrally mounted at an eccentric position avoiding the shaft center of No. 4, and the guide shaft 54 is rotatably mounted on a frame (not shown) by the support shaft 54a. Thus, the gap between the platen 51 and the print head 53 can be adjusted by rotating the guide shaft 54 by, for example, an operation lever (not shown).

According to the printer having such a configuration, the platen gap adjusting mechanism A is adjusted according to a thin slip sheet or a thick slip sheet made up of a plurality of copy sheets.
A predetermined print quality can be maintained without lowering the clarity of the print.

[0008]

The gap between the platen 51 and the paper guide member 55, that is, the paper path gap in the printer having the above-described structure, has some margin (+ α) in the maximum thickness among the usable paper types. ) Is set. For example, as shown in FIG. 5, in consideration of a case where a thick continuous chit sheet made of a plurality of copy papers is used, the fold portion P1 of the so-called zigzag continuous chit sheet is set so as to pass therethrough. .

Therefore, when a thin sheet is inserted, the sheet passes through the outermost periphery of the sheet path gap formed by the sheet guide member 55. When the leading end of the paper P reaches the paper discharge roller 56, the amount of paper deflection is absorbed because the paper feed roller 56 is slightly fed, and the paper P is moved along the platen 51. To pass through the inner circumference position.

[0010] For this reason, there is a technical problem that a slight difference occurs between the printing lines and the printing quality deteriorates.

The present invention has been made in view of such technical problems, and by improving the paper path gap in conjunction with the adjustment of the platen gap, the printing quality can be improved. It is an object of the present invention to provide a printer that can be designed.

[0012]

A paper feeder in a printer according to the present invention, which has been made to achieve the above object, comprises a tractor and / or a paper feed roller for feeding printing paper into a printing area by a print head. A printer provided with a platen arranged to face the print head, and a discharge roller for sending out a print sheet printed by the print head, wherein the fed print sheet is moved along the platen. A sheet guide member for guiding, a paper path gap adjusting mechanism capable of adjusting a gap between the platen, and a platen gap adjusting mechanism capable of adjusting a gap between the platen and the print head; Adjusting the paper path gap by the paper path gap adjusting mechanism, and adjusting the platen by the platen gap adjusting mechanism. Constructed and adjustment of cap so as to be adjusted in conjunction with the operation of the single operating member.

In this case, preferably, the platen gap adjusting mechanism is constituted by a guide shaft which is arranged in parallel with the platen, is rotatable with its axis eccentric, and holds the print head in a reciprocating manner. The paper path gap adjusting mechanism includes a cam member in which a part of the paper guide member abuts along the cam surface, and a spring member for urging the paper guide member in the direction of the cam surface of the cam member. The guide shaft constituting the platen gap adjusting mechanism and the cam member constituting the paper path gap adjusting mechanism are rotated in conjunction with the operation of an operating member.

Further, the platen gap adjusting mechanism includes:
The paper path gap adjusting mechanism is disposed in parallel with the platen, is configured to be rotatable with its axis eccentric, and holds the print head in a reciprocating manner. Equipped with an eccentrically formed groove,
A part of the paper guide member is constituted by a rotation plate engaged with the groove, and a guide shaft constituting the platen gap adjustment mechanism and a rotation plate constituting the paper path gap adjustment mechanism are constituted by an operation member. May be configured to rotate in conjunction with the operation.

According to the paper feeder of the printer configured as described above, the adjustment of the paper path gap and the adjustment of the platen gap can be performed in conjunction with each other by operating one operation member. Can be kept constant.

Therefore, the paper path gap is optimized according to the thickness of the paper, so that the degree of bending of the fed paper can be reduced.
Therefore, even when the sheet is subjected to tension when the leading edge of the sheet is applied to the sheet discharging roller, the sheet is conveyed with little bending, so that the degree of occurrence of print trouble such as so-called elongation is reduced. Can be.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a paper feeder in a printer according to the present invention will be described based on an embodiment shown in the drawings. FIG. 1 is a perspective view showing an example of a print head driving mechanism in a printer.

The print head 1 is fixed to the carriage 2,
The carriage 2 is mounted so as to be able to reciprocate in the print beam direction by a guide shaft 3 and an auxiliary shaft 4 arranged in a horizontal direction. The carriage 2 has a drive pulley 6 attached to a rotation shaft of a carriage motor 5.
And a timing belt 8 stretched between a floating pulley 7 disposed at a position facing the driving pulley 6 in the axial direction of the guide shaft 3 so that the driving pulley 6 can be reciprocated on the guide shaft 3 in the printing girder direction. It is configured.

The print head 1 is of a well-known wire dot impact type which prints by hitting printing paper with a plurality of wires.

FIG. 2 is a sectional view showing a main part of a paper feeding mechanism in the printer. In FIG. 2, the same parts as those in FIG. 1 are indicated by the same reference numerals.

Tractor 1 having pins 11a which engage with perforations provided on both side edges of continuous slip paper
Reference numeral 1 denotes a tractor shaft 11b and a guide shaft 11c, which are provided in front of the paper P transport path and are arranged in parallel with each other.
Thus, the pins 11a that are supported so as to be slidable in the axial directions of both shafts and are driven by a motor (not shown) to engage with the perforations of the paper can be moved in the paper feeding direction. Is configured.

A platen 12 formed in a columnar shape and a sheet guide member 13 for guiding the sheet P along the platen 11 are arranged in the traveling direction of the sheet. Paper guide member 1
3 is provided with a support shaft 13a at one end thereof.
Reference numeral a denotes a paper path gap adjusting mechanism B which is rotatably attached to a frame (not shown), whereby the gap between the paper guide member 13 and the platen 12 can be adjusted.

The paper guide member 13 includes a guide member 13.
A pair of paper feed rollers 15 and 16 urged in the direction of the platen 12 by an expanding spring 14 disposed therein are arranged. The paper feed rollers 15 and 16 are for bringing the paper P into close contact with the platen 12 and smoothly transporting the paper P.

The print head 1 is disposed so as to face the platen 12 in a substantially horizontal direction. As described above, the print head 1 moves on the guide shaft 3 in the print digit direction, that is, the longitudinal direction of the platen 12. The printer is driven reciprocally along the direction, and prints on a sheet by driving a dot wire based on a print signal, as is well known.

The guide shaft 3 will be described in detail with reference to FIG. 3. The guide shaft 3 is eccentrically mounted on a frame (not shown) so as to be rotatable.
7, the platen 12 and the print head 1 are rotated.
And a platen gap adjustment mechanism A that can adjust the gap between the platen gap and the platen gap.

The paper P on which printing has been performed by the print head 1 is discharged by a discharge roller 18 and a pressure roller 19 to a cut sheet guide / sheet receiving guide 20 disposed above the printer. In addition, the discharge roller 18
Is slightly higher than the paper introduction speed by the tractor 11, and the paper P is transported along the platen 12.

FIG. 3 is a schematic diagram for explaining the operation of the platen gap adjusting mechanism A and the paper path gap adjusting mechanism B shown in FIG. 2. The mechanisms will be described together with FIG. As described above, the guide shaft 3 constituting the platen gap adjustment mechanism A holds the carriage 2 on which the print head 1 is mounted so as to be slidable in the axial direction. It is rotatably attached to a frame (not shown) by a support shaft 3a having an axis G at an avoiding position. That is, the guide shaft 3 is configured to be rotatable with its axis center eccentric.

A lever 17 for rotating the guide shaft 3 is attached to the guide shaft 3. Therefore, when the lever 17 is rotated, the carriage 2 is moved along the line FF 'in FIG. Can be moved in any direction. Accordingly, the print head 1 mounted on the carriage 2 moves forward and backward with respect to the platen 12, and can adjust the gap between the platen 12 and the print head 1.

On the other hand, the paper path gap adjusting mechanism B includes a cam member 25 having a cam surface 25a integrally with the lever 17. The cam surface 25a of the cam member 25 is eccentric as shown in FIG. 3 with respect to an arc E indicated by a broken line about the axis G of the support shaft 3a. The expanding spring 2 is moved so that the extension member 13b constituting the portion contacts the cam surface 25a.
1 is interposed between the bottom of the paper guide member 13 and a part of the frame.

Therefore, by rotating the lever 17, the cam member 25 is rotated in the direction of the arrow CC 'about the axis G of the support shaft 3a, and accordingly the cam surface 2 is rotated.
The extension member 13b abutting on 5a moves in the direction of arrow DD '.

As described above, the paper guide member 13 is rotatably attached to a part of a frame (not shown) by the support shaft 13a.
The gap between the platen and the platen 12 is adjusted.

In this case, when the gap by the platen gap adjustment mechanism A is adjusted in the enlargement direction by rotating the lever 17, the gap by the paper path gap adjustment mechanism B is also adjusted in the enlargement direction.

As described above, the platen gap adjusting mechanism A
The paper path gap adjusting mechanism B adjusts each gap in conjunction with the operation of one operation lever. Accordingly, the paper path gap suitable for the adjustment of the platen gap is selected, so that the degree of bending of the fed sheet can be reduced. Therefore, even when the sheet is subjected to tension when the leading edge of the sheet is applied to the sheet discharging roller, the sheet is conveyed with little bending, so that the degree of occurrence of print trouble such as so-called elongation is reduced. Can be.

The paper path gap adjusting mechanism B in the embodiment shown in FIG.
3 is pushed up, for example, when the fold portion P1 of the continuous paper is guided as shown in FIG. The gap is widened, and the paper can be transported smoothly. For this reason, a considerable margin (+
It is not necessary to perform the gap adjustment by adding α), and the paper feeding accuracy can be further improved.

FIG. 4 is a sectional view showing a second embodiment of the paper feed mechanism. The embodiment shown in FIG. 4 includes a rotating plate having a groove formed eccentrically in the rotating direction instead of the cam member 25 in the paper path gap adjusting mechanism B described in FIGS. 2 and 3. There is a characteristic in the point that it is done. Therefore, in FIG. 4, the portions corresponding to FIG. 2 are denoted by the same reference numerals, and detailed description thereof will be omitted.

As shown in FIG. 4, a turning plate 26 is provided integrally with the operation lever 17, and the turning plate 26 has a groove 26a formed eccentrically in the turning direction. . Then, the extension member 13 in the paper guide member 13
b, a rod 13c is attached in the horizontal direction, and the rod 13c is attached to the groove 2 formed in the rotating plate 26.
6a, and is configured to be slid.
The groove 26a is configured to have the same locus as the cam surface 25a shown in FIG.

Accordingly, the turning plate 26 is turned in accordance with the turning operation of the operation lever 17, and the groove 2 formed in the turning plate 26 is rotated.
The extension member 13b is moved up and down along the shape of 6a. Along with this, the paper guide member 13 receives a rotating action about the shaft 13a, and the gap between the paper guide member 13 and the platen 12 is adjusted.

Therefore, the platen gap adjustment mechanism A and the paper path gap adjustment mechanism B are operated in conjunction with each other by operating one operation lever to adjust the respective gaps.

[0039]

As is apparent from the above description, according to the paper feeder according to the present invention, a paper path gap adjusting mechanism capable of adjusting the gap between the platen paper guide member, the platen and the print head And a platen gap adjustment mechanism that can adjust the gap between the paper path gap adjustment mechanism and the platen gap adjustment mechanism using the paper path gap adjustment mechanism. The gap can be adjusted to an optimum state by a single operation of the operation member, and the operability can be facilitated.

In addition, since the paper path gap can be adjusted to an optimum state in accordance with the adjustment of the platen gap, the degree of occurrence of bending in the paper can be reduced, and a high print quality can be guaranteed. Can be provided.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an example of a drive mechanism of a print head in a printer according to the present invention.

FIG. 2 is a sectional view showing a main part of a paper feed mechanism in the printer according to the present invention.

FIG. 3 is a schematic diagram for explaining the operation of the mechanism shown in FIG. 2;

FIG. 4 is a cross-sectional view showing another example of the paper feed mechanism in the printer according to the present invention.

FIG. 5 is a cross-sectional view illustrating an example of a paper feed mechanism in a conventional printer.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Print head 2 Carriage 3 Guide shaft 5 Carriage motor 8 Timing belt 11 Tractor 12 Platen 13 Paper guide member 13a Support shaft 13b Extension member 13c Rod 14 Expanding spring 15 Feed roller 16 Feed roller 17 Operating lever 18 Discharge roller 19 Pressure roller 21 Expanding spring 25 Cam member 25a Cam surface 26 Rotating plate 26a Groove A Platen gap adjustment mechanism B Paper path gap adjustment mechanism P Printing paper P1 Paper fold

Claims (3)

[Claims] 1. A tractor and / or a paper feed roller for feeding print paper to a print area by a print head; and a platen arranged to face the print head.
What is claimed is: 1. A printer provided with a discharge roller for sending out a print sheet printed by the print head, wherein a gap between the platen and a sheet guide member for guiding the fed print sheet along a platen. And a platen gap adjustment mechanism that can adjust the gap between the platen and the print head. The paper path gap is adjusted by the paper path gap adjustment mechanism. A paper feed device for a printer, wherein the adjustment of the platen gap by the platen gap adjustment mechanism can be adjusted in conjunction with the operation of one operation member. 2. The platen gap adjusting mechanism is arranged in parallel with the platen, is configured to be rotatable with its axis being eccentric, and is configured by a guide shaft holding a print head in a reciprocating manner. The paper path gap adjusting mechanism includes a cam member having a part of the paper guide member abutting along the cam surface, and a spring member for urging the paper guide member in the direction of the cam surface of the cam member. A guide shaft constituting a gap adjusting mechanism;
2. The paper feeding device according to claim 1, wherein the cam member constituting the paper path gap adjusting mechanism is rotated in conjunction with the operation of the operation member. 3. The platen gap adjusting mechanism is arranged in parallel with the platen, is configured to be rotatable with its axis being eccentric, and is configured by a guide shaft that holds a print head in a reciprocating manner. The paper path gap adjustment mechanism includes a groove formed eccentrically in the rotation direction, and is configured by a rotation plate in which a part of a paper guide member is engaged with the groove, and the platen gap adjustment mechanism is configured. Guide shaft
2. The paper feeding device of the printer according to claim 1, wherein the rotation plate constituting the paper path gap adjustment mechanism is rotated in conjunction with the operation of the operation member.