JPH1016364A - Ink ribbon winding device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To wind an ink ribbon in one direction at all times by providing an ink ribbon winding driving shaft on one gear of two gears engaged to rotate in the adverse direction mutually, thereby allowing another gear to be engaged with a rack dependent upon its advancing direction at the time of a carriage moving left and right. SOLUTION: When a carriage 3 moves in the forward direction, a first gear 12 comes in engagement with a rack gear 15 so as to rotate a driving shaft 11 for winding an ink ribbon through the rotation of a reel. When moved in the left end, since the carriage 3 turns in its forward and rearward position and moves forward, engagement between the first gear 12 and the first rack is disconnected in order that a second gear 14 and a second rack gear 16 come in engagement with each other. Completion of the carriage in the forwarding movement causes a motor to rotate adversely so that the carriage 3 moves in the adverse direction. At this time, an intermediate gear 13 integrated with the second gear 14 rotates the first gear 12 engaged with the intermediate gear 13 so as to rotate the reel and then wind the ink ribbon.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink ribbon winding device for a printer for printing by reciprocating a print head.
In particular, the present invention relates to an ink ribbon take-up device for a printer that forms one character by printing upper and lower half characters by changing the front and rear positions of a print head between an outward path and a return path.

[0002]

2. Description of the Related Art Generally, in order to take up an ink ribbon using the lateral movement of a printer carriage, it is necessary to always take up the ink ribbon in a fixed direction regardless of the moving direction of the printer carriage. 2. Description of the Related Art Printers that use a switching lever to make the winding direction constant are widely known.

[0003]

However, the winding of the ink ribbon using the ratchet or the switching lever requires a large number of parts, so that the manufacturing and assembling steps are simplified and the manufacturing cost is reduced. It is difficult to achieve the above, and the ink ribbon is wound when moving from the home position or when switching the front and rear positions of the print head out of the printable area and when moving the printer carriage to that position. Therefore, the consumption of the ink ribbon is accelerated, and in the case of an endless ribbon that is used repeatedly, a portion where the ink is not used exists at random, so that the density of the ink varies, which causes printing unevenness. There was a risk of becoming one.

SUMMARY OF THE INVENTION The present invention solves the above-mentioned problems and has a simple structure, in which the ink ribbon is always wound in a fixed direction in conjunction with the horizontal movement of the printer carriage, the consumption of the ink ribbon is suppressed, and the consumption of ink is reduced. It is an object of the present invention to provide an ink ribbon take-up device that reduces printing unevenness by achieving uniformity, and that is excellent in mounting properties when replacing an ink ribbon cassette.

[0005]

In order to solve the above-mentioned problems, an ink ribbon take-up device according to the present invention reciprocates a printer carriage loaded with an ink ribbon cassette to the left and right. An ink ribbon take-up device for a printer that performs reciprocal printing by changing a first gear having a drive shaft that rotates on a drive shaft that rotates with the reel of the ink ribbon cassette; A second gear linked to a gear and rotating in a direction opposite to the first gear; and a first gear disposed along the moving direction of the printer carriage and corresponding to the switching of the front-rear position of the printer carriage. A rack gear selectively meshes with the gear and the second gear, and rotates the meshed gear in conjunction with the movement of the printer carriage.

It is desirable that the rack gear is arranged only in a printable area.

Further, the first gear and the second gear may be replaced with a first roller and a second roller, respectively, and the rack gear may be replaced with a rail.

[0008]

FIG. 1 shows a printer to which an ink ribbon winding device according to the present invention is applied. This printer drives a belt 2 via a speed reduction mechanism composed of a plurality of gears using a motor 1 as a drive source, guides a printer carriage 3 connected to the belt 2 by a guide shaft 4, and rotates the motor 1 forward and backward. By rotating, the printer carriage 3 is moved right and left, and reciprocating printing is performed by the print head 5 mounted on the printer carriage 3.
By using a switching mechanism (not shown), the front-back position is changed by half a character, the front-back position of the print head 5 mounted on the printer carriage 3 is changed, and the print-receiving sheet 7 placed on the printing table 6 is moved without moving. It prints large characters with the print head.

The printer carriage 3 has a first gear 12 which engages with a reel of the ink ribbon cassette 10 mounted thereon and has a drive shaft 11 for rotating the reel as a rotation axis; An intermediate gear 13 that meshes with the second gear 12 and a second gear 14 that is formed integrally with the intermediate gear 13 and that has the same diameter and rotates in the opposite direction to the first gear 12 are arranged.

In the printer body, a first rack gear 15 and a second rack gear 16 are arranged in parallel at a predetermined interval along the moving direction of the printer carriage 3. The first rack gear 15 and the second rack gear 16 are formed to have substantially the same length as the platen 17 which is a printable area. When the printer carriage 3 moves to the left (forward direction), as shown in FIG. As shown in a)
When the first gear 12 meshes with the first rack gear 15 and the printer carriage 3 moves rightward (reverse direction), as shown in FIG. 2B, the printer carriage 3 moves at the position where the printer carriage 3 has moved forward. , The second gear 14 is arranged to mesh with the second rack gear 16.

In the vicinity of the starting point (home position) and the ending point of the outward path, the gears 12 and 14 are rack gears 15 and
Since the length of the rack gears 15 and 16 is substantially the same as the length of the platen 17 (printable area) so as not to mesh with the print head 16, the print head 5 can print as shown in FIG. Only when moving within the region, the first gear 12 is in the first rack gear 15 and the second gear 14 is in the second rack gear 15.
The rack gears 16 are provided so as to mesh with each other.

According to the ink ribbon winding device having the above structure, when the printer carriage 3 moves in the forward direction (outbound path), as shown in FIG.
Of the first gear 12
Rotates clockwise as indicated by the arrow, and the drive shaft 11, which is a rotating shaft, rotates clockwise to rotate the reel clockwise to wind up the ink ribbon. When the printer carriage 3 moves to the left end, the front and rear positions are switched to move forward, so that the first gear 12 and the first rack gear 15 are disengaged from each other, and the second gear 14 and the second rack gear 16 Meshes. When the forward movement of the printer carriage 3 is completed, the motor 1 rotates in the reverse direction, is driven by the belt 2, and the printer carriage 3 moves in the reverse direction (return path). When the printer carriage 3 moves in the reverse direction, the second gear 14 and the second rack gear 16 are engaged with each other as shown in FIG.
Gear 14 rotates counterclockwise as indicated by the arrow. Since the intermediate gear 13 integrated with the second gear 14 also rotates counterclockwise, the first gear 12 meshed with the intermediate gear 13 rotates clockwise, the drive shaft 11 that is the rotating shaft rotates clockwise, and the reel is rotated rightward. Rotate to take up the ink ribbon. Therefore, if the printer carriage 3 moves, it does not depend on the moving direction, and the drive shaft 11, which is the rotation shaft of the first gear 12, always rotates in a certain direction, and winds the ink ribbon in a certain direction. Can be taken.

Since the rack gears 15 and 16 are formed to have substantially the same length as the platen 17, the gears 12 and 14 are provided near the start point and the end point where the print head 5 deviates from the platen 17 which is a printable area. And the rack gears 15 and 16 are disengaged from each other, and the gears 12 and 14 do not rotate. Therefore, the drive shaft 11 is free, and the ink ribbon is not wound up at a portion where printing is not necessary.

According to the above-described ink ribbon take-up device, the printer carriage 3 is disposed on the printer carriage 3 because the front and rear positions thereof change depending on whether the moving direction is a forward direction (outward path) or a reverse direction (return path). The first gear 12 and a second gear 14 that engages with the first gear 12 and rotates in a direction opposite to the first gear 12 selectively engage with the rack gear. The drive shaft 11, which is the rotating shaft of 12, can always be rotated in a fixed direction for winding the ink ribbon.

When the print head 5 is out of the printable area, the drive shaft 11 becomes free, so that the ink ribbon is not fed idly, and the portion using ink and the portion not using ink are separated. Since there is no mixture, the consumption of ink that has soaked into the ink ribbon becomes uniform,
Printing unevenness due to the density of the ink is reduced.

Furthermore, when the front and rear positions of the printer carriage 3 are switched, the gear and the rack gear are not switched while being engaged, so that no load is applied to the switching mechanism and the gear or the rack gear is prevented from being damaged. it can.

Since the drive shaft 11 is free at the home position (starting point), the mountability when replacing the ink ribbon cassette is improved.

In the above-described ink ribbon winding device,
Although the gear is rotated by a rack gear, a roller formed of rubber, metal, synthetic resin, or the like may be used instead of the gear and the rack gear, and a rail for rolling the roller. In this case, unlike the meshing, the contact between the roller and the rail can be smoothly performed at the time of the direction change.

Further, as shown in FIG. 5, intermediate gears 23 and 24 having the same diameter are integrally formed with the first gear 21 and the second gear 22 having the same diameter, respectively. 24 and the first gear 21 is connected to the rack gear 1.
5 and the second gear 22 may be driven by the rack gear 16.

According to this ink ribbon take-up device, the amount of rotation of the first gear 21 with respect to the amount of movement of the printer carriage 3 (the amount of rotation of the drive shaft 11) is always the same regardless of the direction of movement of the printer carriage 3. Therefore, the winding amount of the ink ribbon can be kept constant at all times.

As shown in FIG. 6, a first gear 26 in which a drive shaft 11 is formed on the front side and an intermediate gear 25 is integrally formed on the back side, and a first gear 26 having the same diameter meshed with the intermediate gear 25 are provided. The intermediate gear 27 may be integrally formed on the front side, and the second gear 28 having the same diameter as the first gear 26 may be rotated by one rack gear 29.

According to this ink ribbon take-up device, when the printer carriage 3 moves in the forward direction, the first gear 26 meshes with the rack gear 29, rotates the drive shaft 11 clockwise, and moves in the reverse direction. At this time, since the printer carriage 3 moves forward, the second gear 28 meshes with the rack gear 29, and the second gear 28 rotates counterclockwise, so that the first gear 26 through the intermediate gears 27 and 25. Is rotated clockwise, so that the drive shaft 11 for winding the ink ribbon can always be rotated in a fixed direction even when the printer carriage 3 is moving in either the left or right direction with one rack gear.

[0023]

According to the first aspect of the present invention, a drive shaft for winding the ink ribbon is provided in one of the two gears linked so as to rotate in directions opposite to each other, and the printer carriage is moved right and left. When moving, the different gears mesh with the rack gear according to the direction of travel, and the driven shaft always rotates in one direction due to the rotation of the meshed gear, so that it is influenced by the direction of travel of the printer carriage with a simple structure. Therefore, the ink ribbon can always be wound in one direction.

According to the second aspect of the present invention, when the rack gear is arranged only in the printable area, the drive shaft is free outside the printable area and the ribbon is not wound.
An ink ribbon take-up device that not only reduces the consumption of the ink ribbon, makes it possible to achieve uniform ink consumption, reduces printing unevenness, and has excellent mounting properties when replacing the ink ribbon cassette. Can be provided.

According to the third aspect of the invention, the contact between the roller and the rail at the time of turning can be smoothly performed.

[Brief description of the drawings]

FIG. 1 is a plan view showing a main part of a printer to which an ink ribbon winding device according to the present invention is applied.

FIGS. 2A and 2B are explanatory diagrams of an operation mode of the ink ribbon winding device.

FIG. 3 is a plan view showing a relationship between a rack and gears of the ink ribbon winding device.

FIGS. 4A and 4B are plan views of main parts for explaining an operation mode of the ink ribbon winding device.

FIG. 5 is a plan view showing another example of the ink ribbon winding device.

FIG. 6 is a plan view showing an operation mode of still another example of the ink ribbon winding device.

[Explanation of symbols]

 Reference Signs List 3 Printer carriage 5 Print head 10 Ink ribbon cassette 11 Drive shaft 12 First gear 14 Second gear 15, 16 Rack gear

Claims (3)

[Claims] 1. An ink ribbon take-up device for a printer for reciprocatingly moving a printer carriage loaded with an ink ribbon cassette to the left and right, and changing the front and rear positions by half a character between a forward path and a backward path to perform reciprocal printing. A first gear that is engaged with a reel of the set and has a drive shaft that rotates the reel as a rotation axis; a second gear that is linked to the first gear and rotates in a direction opposite to the first gear; , Are arranged along the moving direction of the printer carriage,
And a rack gear that selectively meshes with the first gear and the second gear in response to switching of the front and rear positions of the printer carriage, and that rotates the meshed gear in conjunction with the movement of the printer carriage. An ink ribbon winding device. 2. The ink ribbon winding device according to claim 1, wherein the rack gear is arranged only in a printable area. 3. The ink ribbon take-up device according to claim 1, wherein the first gear and the second gear are replaced with a first roller and a second roller, respectively, and the rack gear is replaced with a rail. apparatus.