JP3233008B2 - Loading device for ribbon cartridge in thermal transfer printer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for loading a ribbon cartridge in a thermal transfer printer, and more particularly to improving operability when loading a ribbon cartridge.

[0002]

2. Description of the Related Art FIG. 4 shows an example of a conventional thermal transfer printer. In the figure, a ribbon cartridge 1 contains a pair of ribbon rolls 2 and a ribbon 4 wound around them. The ribbon cartridge 1 is loaded so that it can be inserted and removed in the axial direction of a pair of winding shafts 3 of the thermal transfer printer main body, and the hub of each ribbon roll 2 engages with the winding shaft 3 to transport the ribbon 4. I do. Then, the thermal head 5 presses against the platen roller 7 with the ribbon 4 and the recording paper 6 interposed therebetween, and generates heat according to the image information, thereby transferring characters and images.

Next, in the above-mentioned conventional thermal transfer printer,
The loading device of the ribbon cartridge is specifically shown. FIG. 5 is an exploded perspective view of the take-up shaft 3. A gear 9 having an annular projection 9a having an arc-shaped notch in the center is press-fitted to a rotary shaft 11 extending from the thermal transfer printer main body. It rotates integrally with the rotating shaft 11. A cap 8 is inserted into the rotating shaft 11. An annular projection 8a having an arc-shaped notch is provided on one side of the cap 8 so as to engage with the annular projection 9a, and a ribbon cartridge is provided on the other side. Three pawls 8b to be engaged with one hub are formed.

The two annular projections of the cap 8 and the gear 9 differ in the length of the arc of each notch, and intentionally have a play in the rotational direction. The cap 8 is urged by a spring 10 so that the cap 8 elastically moves in the axial direction of the rotation shaft 11 with the insertion and removal of the ribbon cartridge 1. The E-ring 12 prevents the cap 8 from moving in the axial direction. Regulating.

In the above-described configuration, when the gear 9 rotates with the rotation of the rotating shaft 11, the side faces of the notches of the annular projections 8a, 9a come into contact with each other, and the cap 8 rotates.
And three similar claws (not shown) provided at the same interval on the hub of the ribbon roll 2 of the ribbon cartridge 1;
The pawl 8b of the cap comes into contact with the cap to transmit the rotational force.

If the hook of the hub and the hook 8b of the cap 8 face each other at the same angle when the ribbon cartridge 1 is loaded, the ribbon cartridge 1 cannot be loaded. Therefore, as described above, the cap 8 is slightly rotated to either side due to the play between the annular projections 8a and 9a provided intentionally to facilitate loading of the ribbon cartridge.

[0007]

However, according to the above-mentioned conventional structure, when the claws of the cap and the claws of the hub of the ribbon cartridge face each other, it is not always possible to smoothly rotate the cap and perform smooth loading. That is, as shown in FIG. 6, each annular projection 8a, 9a of the cap 8 and the gear 9
Assume that the claw 8b of the cap and the claw of the hub face each other in a state where the abutment is in contact. At this time, cap 8
If the is rotated in the direction of the arrow, the ribbon cartridge can be loaded, but in the state shown in the figure, the cap 8 can rotate in the direction of the arrow, and the gear 9 does not rotate.
The ribbon cartridge cannot be inserted.

[0008]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention engages an arc-shaped slit formed on a gear with an arc-shaped projection formed on a cap to rotate the gear. A ribbon cartridge loading device configured to communicate to the ribbon cartridge through a cap,
The cap is configured to be movable in the axial direction of the rotating shaft between when the ribbon cartridge is loaded and when the ribbon cartridge is not loaded, and when the ribbon cartridge is loaded, the projections are engaged without looseness in the slits. The protrusion is formed by changing the length of the arc so that there is play between both ends and the slit.

Accordingly, even if the claws of the ribbon cartridge and the claws of the cap face each other, it is possible to always smoothly load them.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS According to the first aspect of the present invention, a ribbon cartridge can be inserted into and removed from a ribbon winding shaft provided on a thermal transfer printer main body in the axial direction thereof.
And a device for loading the ribbon so that the hub of the ribbon roll of the ribbon cartridge and the winding shaft engage with each other so that the ribbon can be transported, wherein the winding shaft rotates integrally with a rotation shaft, A gear having an arc-shaped slit centered on the rotation axis, and, on one side, an arc-shaped protruding portion that engages with the slit of the gear to transmit the rotational force of the gear, A cap having a claw that engages with the hub to transmit the rotational force; and a first position in which the gear and the cap are separated when the ribbon cartridge is not loaded. A spring that resiliently biases the cap in the direction of the first position so that the cap is pressed by the ribbon cartridge and is located at the second position close to the gear; Is At the first position, there is a backlash in the rotational direction between the slit on both sides of the protrusion, and at the second position, from the root of the protrusion, so as to abut against both ends of the slit without play. An apparatus for loading a ribbon cartridge in a thermal transfer printer, characterized in that the length of the arc is reduced toward the leading end.

According to the above-mentioned structure, when the ribbon cartridge is not loaded, the cap claw and the hub claw of the ribbon cartridge face each other because both sides of the projecting portion of the cap can be made to play. Sometimes, the cap can always be rotated in either direction, so that the ribbon cartridge can always be loaded smoothly.

(Embodiment 1) An embodiment of the present invention will be described below with reference to the drawings. The ribbon cartridge loading device of the present embodiment differs from the above-described conventional configuration only in the configuration of the cap and gear of the take-up shaft. Hereinafter, the different points will be mainly described.

FIG. 1 is an exploded perspective view of a winding shaft in the loading device according to the present embodiment. The difference from the conventional structure is that a cap 9 has an arc-shaped slit 13 around a rotation shaft 11. And the point that an arc-shaped protruding portion 14 that engages with the slit 13 is formed on the cap 8. The protruding portion 14 is formed such that the length of the arc is substantially equal to the length of the slit 13 at the root, and the length of the arc gradually becomes shorter than the slit 13 toward the center of the tip. The cap 8 is biased in a direction in which the gear 9 and the cap 8 are separated from each other by a spring 10 provided on the annular projecting portion 9a of the gear 9.
The movement is restricted by the ring 12.

Next, the operation of the winding shaft when the ribbon cartridge is loaded will be described. When the ribbon cartridge is not loaded, as shown in FIG.
And the gear 9 are in a first position spaced apart from each other,
The tip of the projection 14 of the cap 8 is engaged with the slit 13. As for the positional relationship between the two, as shown in FIG. 2B, the protrusion 14 is located at the center of the slit 13 and the protrusion 14 has a play in both rotation directions.

When the ribbon cartridge is loaded, as shown in FIG. 3A, the cap 8 is located at the second position where the cap 8 and the gear 9 are close to each other by the spring 10 against the ribbon cartridge. At this time, as shown in FIG. 3B, the root of the projection 14 of the cap 8 engages with the slit 13 of the gear 9, and no rattling occurs on both sides of the projection 14. When the gear 9 rotates in this state, the cap 8 also rotates, and the rotational force is transmitted to the ribbon cartridge. When the ribbon cartridge is removed, the cap 8 is moved in the direction of the first position by the spring 10, so that the positional relationship between the protruding portion 14 of the cap 8 and the slit 13 of the gear 9 is again as shown in FIG. .

Here, consider the case where the claws of the hub of the ribbon cartridge and the claws 8b of the cap 8 collide when the ribbon cartridge is loaded in the state of FIG. At this time, since there is always play on both sides of the projecting portion 14 of the cap 8, the cap 8 can be rotated in either direction, so that the claw 8b of the cap 8 escapes from the claw of the ribbon cartridge and can be smoothly loaded.

When the ribbon cartridge is securely loaded, the projection 14 of the cap 8 and the slit 13 of the gear 9 are in the state shown in FIG. For this reason, when the ribbon cartridge is removed, the state in which the projection 14 is almost in the middle of the slit 13 can be always maintained, and the projection 14 does not approach the end of the slit 13.

[0018]

As described above, according to the present invention, when the ribbon cartridge is not loaded, the play of the cap can be always secured in both rotation directions. However, since the claw of the cap escapes reliably, there is no possibility that the ribbon cartridge cannot be loaded as in the related art.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view of a main part of a ribbon cartridge loading device of a thermal transfer printer according to an embodiment of the present invention.

FIG. 2 is an essential part perspective view showing a state where the ribbon cartridge of the apparatus is not loaded.

FIG. 3 is an essential part perspective view showing a state when the ribbon cartridge of the apparatus is loaded.

FIG. 4 is a main part side view showing an example of a thermal transfer printer to which the present invention is applied.

FIG. 5 is an exploded perspective view of a main part showing a ribbon cartridge loading device of a conventional thermal transfer printer.

FIG. 6 is an essential part perspective view showing a loading operation of the ribbon cartridge of the apparatus.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Ribbon cartridge 2 Ribbon roll 3 Take-up axis 4 Ribbon 5 Thermal head 6 Recording paper 7 Platen roller 8 Cap 9 Gear 10 Spring 11 Rotation axis 12 E-ring 13 Slit 14 Projection

──────────────────────────────────────────────────続 き Continued on the front page (58) Fields surveyed (Int. Cl. ⁷ , DB name) B41J 35/28 B41J 17/22-17/26 B41J 17/32 G11B 15/675 B65H 19/00

Claims (1)

(57) [Claims] A ribbon winding shaft provided on a main body of a thermal transfer printer so that a ribbon cartridge can be inserted and removed in an axial direction thereof, and a hub of a ribbon roll of the ribbon cartridge is engaged with the winding shaft. A gear having an arc-shaped slit that rotates integrally with a rotating shaft and has an arc-shaped slit centered on the rotating shaft. Has an arc-shaped projection that engages with the slit of the gear to transmit the rotational force of the gear, and has a claw on the other side that engages with the hub to transmit the rotational force. When the ribbon cartridge is not loaded, the cap is pressed by the ribbon cartridge to a first position at which the gear and the cap are separated when the ribbon cartridge is loaded, and the second position is set close to the gear when the ribbon cartridge is loaded. So as to be positioned in the location,
A spring that resiliently biases the cap in the direction of the first position, wherein the protrusion of the cap in the first position is rotated in a rotational direction between the slits on both sides of the protrusion. Rattling occurs, the second
In the position (1), the length of the arc is shortened from the root to the tip of the protruding portion so as to make contact with both ends of the slit without play.