JPS62170377A - Ribbon cartridge - Google Patents

Abstract

PURPOSE:To enable a stable tension to be constantly applied to an ink film, by providing an ink film guide roller provided with a one-way clutch. CONSTITUTION:In a thermal transfer printer in which a ribbon cartridge is inverted to print by a printing region other than a used printing region, when a printing head is pressed against a platen 12 and is started scanning rightward, an ink film 1 passed through the printing head 11 is paid out while being taken up by a ribbon spool 2. A guide roller 14 on the payout side is provided with a one-way clutch 14a which can be rotated in the direction of the arrow but can not be rotated in the opposite direction. Therefore, a braking tension is applied to the ink film 1. When the ribbon cartridge 4 is inverted, the guide roller 14 comes to a position 14' on the take-up side. In this case, the guide roller 14' is lightly rotated in the direction of the arrow, so that it is unnecessary to increase the torque of a take-up side driving motor, and an appropriate tension can be applied to the ink film on the take-up side.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention applies constant pressure to the print head during printing, and prints on the printing paper sandwiched between the platen and the printing gutter via a heat-sensitive film ribbon. The present invention relates to a ribbon cartridge for a thermal transfer printer.

[Conventional technology]

Conventionally, in ribbon cartridges used in thermal transfer printers, wrinkles and
Although measures are taken to prevent skew and print stains, there were no particular problems when using the ribbon in one direction. However, in order to extend the lifespan of the same ribbon cartridge, when reversing the ribbon cartridge and performing reciprocating printing, the winding side is set to the feeding side, so friction brake mechanisms are required on both sides, but conventionally the same brake It was a mechanism.

[Problem that the invention seeks to solve]

As mentioned above, conventional ribbon cartridges are equipped with the same friction brake on both the take-up side and the unwinding side, so the unwinding side applies an appropriate braking force to prevent wrinkles, skews, etc. from occurring in the ink film. Film tension can be added, but on the winding side, a braking effect is generated against the winding force, which not only requires increasing the torque of the winding side drive motor, but also due to changes in the friction coefficient of the friction plate over time. The tension applied to the ink film fluctuates, resulting in wrinkles, skew, print stains, etc.

An object of the present invention is to provide a ribbon cartridge that always provides stable film tension to the ink film.

[Means for solving problems]

The present invention is a thermal transfer printer that has two printing ranges, upper and lower, and after printing on the upper or lower row is completed, the ribbon cartridge is reversed and printing is performed using a printing range different from the used printing range. This ribbon cartridge is characterized in that it has an ink film guide roller equipped with a one-way clutch that does not rotate in the ink film running direction when the ribbon cartridge rotates, but rotates in the ink film running direction when it is reversed and located on the winding side.

〔Example〕

Next, the present invention will be explained with reference to the drawings.

FIG. 1 is a plan view of an embodiment of the present invention, and FIG. 2 is a front view. In FIG. 1 and FIG. 2, the ink film 1 has a ribbon spool 2 on the winding side and a ribbon spool 3 on the feeding side.
and is built into the ribbon cassette 4. The ribbon cassette 4 is mounted on the carrier frame 5,
The two carrier guide shafts 6 are scanned in the platen axis direction by a drive source (not shown). A ribbon drive motor 7, a torque gear 8, and a torque piece 9 are mounted on the carrier frame 5, and wind up the ink film 1 that is fed out by printing. The retraction solenoid 10 is located on the back side of the print head 11 and connects the print head 11 to the platen 12.
During printing, the ink film 1 and printing paper 13 are sandwiched between them. The present invention includes two ink film guide rollers 14, 14' and one-way clutches 14a, 14a.
By implementing ', when the ink film is located on the feeding side, rotation is prevented in the feeding direction of the ink film, and an appropriate brake is applied due to the frictional force with the ink film, and when it is located on the winding side, it rotates lightly. It is designed to eliminate frictional load. The ink ribbon 1 is guided at four locations: two guide rollers 14 and 14' with built-in one-way clutches and a guide roller 15 and 15'.

Next, the operation of the present invention will be explained.

When printing is started and the print head is pressed against the platen 12 and begins to scan in the right direction, the ink film 1 is fed out while being wound around the ribbon spool 2 through the print head 11. At this time, since a one-way clutch 14a is mounted on the guide roller 14 located on the feeding side, which can rotate in the direction of the arrow but cannot rotate in reverse, brake tension is generated in the ink film 1.

This applies feeding tension to the ink film 1, thereby preventing wrinkles, skew, and print stains during printing. When the ribbon cartridge 4 is reversed, the guide roller 14 is at the position 14' and becomes the winding side. At this time, the kite roller 14' rotates slightly in the direction of the arrow, so
There is no need to increase the torque of the drive motor 7 on the winding side, and the film tension on the winding side can also apply an appropriate load.

〔Effect of the invention〕

As explained above, in order to extend the life of thermal transfer ink film, the present invention implements a one-way clutch in the guide roller of a reversible ribbon cartridge that has two printing ranges, upper and lower, and the feeding side does not rotate in the ink film running direction. When the brake force is applied and the ink film is located on the take-up side, it is rotated slightly in the take-up direction, thereby constantly applying stable film tension to the ink film, allowing the ink film to run stably and achieving good print quality. There is.

[Brief explanation of drawings]

FIG. 1 is a plan view showing an embodiment of the present invention, and FIG. 2 is a front view thereof. 1... Ink film, 14. 14'... Guide roller, 14a, 14a'... One-way clutch. Figure 2

Claims (1)

[Claims] (1) In a thermal transfer printer that has two printing ranges, upper and lower, after printing on the upper or lower row is completed, the ribbon cartridge is reversed and printing is performed using a printing range different from the used printing range, and the printer is located on the side where the ink film is fed out. A ribbon cartridge characterized in that it has an ink film guide roller equipped with a one-way clutch that does not rotate in the ink film running direction when it is reversed and rotates in the ink film running direction when it is located on the winding side.