JPH043917B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to an ink ribbon cassette for a printer or the like used as an output terminal for a computer or the like.

2. Description of the Related Art A conventional printer having a reverse rotation prevention device for a ribbon winding hub is disclosed, for example, in Japanese Patent Application Laid-Open No. 56-62183. The conventional ink ribbon cassette will be described below with reference to the accompanying drawings. In FIG. 3, 1 is an ink ribbon cassette case, and 2 is a supply reel rotatably placed within the ink ribbon cassette case 1. In FIG.
Reference numeral 3 denotes an ink ribbon, which is wound around the supply reel 2, and printing ink is coated and fixed on a film base, and the printing ink is transferred onto the receiving paper by a printing means. A ribbon winding hub 4 is driven by a motor (not shown) of the printer body, and winds up the ink ribbon 3 used for printing. During printing, the ink ribbon cassette case 1 is mounted on a carriage (not shown), and the carriage repeatedly moves back and forth between the printing widths. Once the ink ribbon cassette case 1 is removed from the carriage, the ribbon take-up hub 4 can rotate both in the direction of arrow C and in the direction of arrow D in FIG.

Problems to be Solved by the Invention However, in the ink ribbon cassette having such a configuration, when the ink ribbon cassette is removed from the carriage, the ink ribbon 3 that has been used for printing and is wound around the ribbon winding hub 4 is removed.
may be pulled out of the ribbon winding hub 4 by a finger or for some other reason (vibration, etc.). Further, the supply reel 2 and the ribbon take-up hub 4 may also rotate in the opposite direction. As a result, if the ink ribbon cassette in the above state is loaded into the carriage again and printing is performed, the ink ribbon 3 that has been used for printing and the printing ink has drained will be used again for printing, which will reduce the print quality. It had the problem of causing irritation. In addition, if the part of the ink ribbon 3 that protrudes from the cassette case 1 becomes slack, the transfer paper (not shown)
At the time of insertion, the end of the transfer paper got caught on the part of the ink ribbon 3 protruding from the cassette case 1, making it impossible to feed the transfer paper smoothly.

Furthermore, since the conventional reverse rotation prevention mechanism of the ribbon winding hub 4 is provided on the carriage, it cannot be easily replaced, so it must be designed to have a long life.

Therefore, the present invention prevents the ink ribbon once used for printing and wound around the ribbon winding hub from being reversed even when the ink ribbon cassette is removed from the carriage.
This prevents the used ink ribbon from being used for printing again and ensures good print quality. At the same time, it prevents the ink ribbon from sagging and allows for smooth transfer paper feeding. It is something to do.

Furthermore, by making it possible to replace the reverse rotation prevention device of the ribbon take-up hub at the same time as replacing the ink ribbon cassette, the design becomes easier because a reverse rotation prevention device with a short life can be used. Even if a prevention device is installed, the ink ribbon cassette can be made thinner.

Means for Solving the Problems The present invention solves the above-mentioned conventional problems.
The ribbon take-up hub housed in the ink ribbon cassette is equipped with a one-way clutch mechanism. It is made up of a coil spring that is biased and whose tip engages with the claw.

Effect The effect of this technical means is as follows.

In other words, even when the ink ribbon cassette is removed from the carriage, even if the ink ribbon used for printing and wound around the ribbon take-up hub is reversed by a finger or some other cause (vibration, etc.), the ink ribbon will not end up on the ribbon take-up hub. The provided one-way clutch mechanism prevents the ribbon take-up hub from reversing, preventing the used ink ribbon from reversing, and also serves as a stopper in the one-way clutch mechanism even if the one-way clutch mechanism is mounted on the ink ribbon cassette. By constructing the ink ribbon cassette with a coil spring, the ink ribbon cassette can be made thinner by making the member that functions as the stopper thinner.

Embodiments Hereinafter, embodiments of the present invention will be described based on the accompanying drawings. In Fig. 1, 1 is an ink ribbon cassette case, and 2 is an ink ribbon cassette case 1.
This is a supply reel rotatably placed inside the tank. 3
Printing ink is applied to a film base, and an ink ribbon is wound around a supply reel 2, and the printing ink is transferred onto a receiving paper by a printing means. Reference numeral 4 denotes a limbo winding hub which is driven by a motor (not shown) in the limbo main body and winds up the ink ribbon 3 used for printing. Furthermore, the ribbon winding hub 4
A plurality of claws 5 of a one-way clutch mechanism are provided circumferentially on at least one of the lower surface and the upper surface. 6 is a torsion coil spring whose other end is fixed and serves as a stopper in a one-way clutch mechanism. Reference numeral 7 denotes a back tension spring for applying tension to the ink ribbon 3 and at the same time regulating the amount of the ink ribbon 3 to be drawn out from the supply reel 2. Direction A is the direction of rotation of the ribbon take-up hub 4 during printing.

Next, the operation of the configuration of this embodiment will be explained using FIG. 2. When performing normal printing, the ribbon winding hub 4 rotates in the A direction. At this time, the tip of the torsion coil spring 6 is pushed by the claw 5 provided on the ribbon winding hub 4 and moves away from the claw 5, that is, in the direction B. As a result, the ribbon take-up hub 4 can rotate in the direction A and take up the ink ribbon 3.

However, when the ink ribbon cassette is removed from the carriage or installed in the carriage, even if the ribbon take-up hub 4 is rotated by a finger or some other cause (vibration, etc.) in the opposite direction to the rotation direction A during printing, the ribbon Rotation is prevented by the engagement of the tip of the torsion coil spring 6 with a claw 5 provided on the winding hub 4,
Used ink ribbon 3 from ribbon winding hub 4
withdrawal is prevented.

By providing the one-way clutch mechanism on the ribbon take-up hub 4 as described above, it is possible to prevent the used ink ribbon 3 from being pulled out from the ribbon take-up hub 4.

Effects of the Invention The present invention includes a one-way clutch mechanism in the ribbon winding hub housed in the ink ribbon cassette as described above, and a plurality of one-way clutch mechanisms provided on the circumference of the ribbon winding hub. The structure consists of a claw and a coil spring whose tip is biased toward the ribbon take-up hub and whose tip engages with the tab, so even if a one-way clutch mechanism is installed in the ink ribbon cassette, the one-way clutch mechanism will not work. By constructing the member that acts as a stopper with a coil spring, the ink ribbon cassette can be made thinner by making the member that acts as the stopper itself thinner, and it is possible to prevent the ink ribbon from reversing. As a result, devices such as printers that use ink ribbon cassettes can be made thinner, and at the same time, good print quality can be obtained because the ink ribbon that has been used for printing will not be used again. Since the portion of the ink ribbon protruding from the cassette case can be prevented from sagging, contact between the transfer paper and the ink ribbon when feeding the transfer paper can also be prevented.

Furthermore, since the reverse rotation prevention mechanism can also be replaced when replacing the ink ribbon cassette, the design can be made without considering the life of the reverse rotation prevention mechanism.

[Brief explanation of drawings]

FIGS. 1a and 1b are a plan view and a sectional view of an ink ribbon cassette in an embodiment of the present invention, and FIG.
The figure is an enlarged plan view of the same essential parts, and FIG. 3 is a plan view showing a conventional ink ribbon cassette. 1... Ink ribbon cassette, 2... Supply reel, 3... Ink ribbon, 4... Ribbon winding hub, 5... Pawl, 6... Torsion coil spring.

Claims (1)

[Claims] 1 has a supply reel wound with an ink ribbon and a ribbon winding hub for winding the ink ribbon;
The ribbon winding hub is provided with a one-way clutch mechanism for preventing reverse rotation, and the one-way clutch mechanism is connected to a plurality of claws provided on the circumference of the ribbon winding hub, and a tip thereof is located on the ribbon winding hub side. 1. An ink ribbon cassette comprising a coil spring which is biased by the ink ribbon and whose tip engages with the claw.