JPH0420061Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a head up-down device that is installed in a thermal printer and that lowers the head toward the platen or raises the head toward the platen.

[Conventional technology]

Conventionally, this type of head up-down device includes a carriage support plate which movably supports a carriage on which a head mounting base for holding a head is mounted, and which is attached to be rotatable about an axis supported by a chassis, and a carriage support plate which is rotatably mounted on a shaft supported by a chassis. Some devices include a moving body such as a rack that rotates the support plate, an actuator that restricts the movement of the rack, and a solenoid that drives the actuator.

This conventional head up-down device lowers the head in the direction closer to the thermal printer during printing by rotating the carriage support plate as the rack moves, and presses the head against the platen. The ink of the ink ribbon is melted and transferred onto the recording paper, and when not printing, the head is raised in the direction away from the platen, and the recording paper is fed around the platen.
This allows the carriage to be moved to the home position, etc. In particular, when the head is raised, the movement of the rack is restricted by a solenoid to maintain the head in the up state, thereby making it possible for the carriage to move to the above-mentioned home position or the like.

[Problems to be solved by the invention] By the way, the conventional head up device configured as described above has a solenoid that regulates the movement of the rack in order to maintain the head up state, and this solenoid Since they are generally expensive, they have the disadvantage of increasing manufacturing costs.

The present invention has been made in view of the above-mentioned actual state of the prior art, and its purpose is to provide a head up-down device that can maintain the head up state without requiring a solenoid.

[Means for solving problems]

In order to achieve this object, the present invention includes a head mount that holds the head rotatably provided on the carriage, a gear portion formed in the head mount, and a gear means that engages with the gear portion. A cam that can be engaged with the head mount is rotatably mounted on the carriage, and an elastic member such as a spring is provided to urge the cam and the head mount to engage. .

[Effect]

Since the present invention is configured as described above,
The head is rotated in accordance with the movement of the moving object, making it possible to raise and lower the head, and when the head is raised, the head mounting base and the cam are engaged by the elastic force of the elastic member, realizing a so-called mechanical lock. Therefore, the head can be kept in the open state without requiring a solenoid.

〔Example〕

Hereinafter, the head up-down device of the present invention will be explained based on the drawings.

Figures 1 to 3 are explanatory diagrams showing one embodiment of the present invention, in which Figure 1 is a sectional side view of the main part showing the head-down state, and Figure 2 shows the state of transition between the head-down and head-up states. FIG. 3 is a side sectional view of the main part showing the head when it is opened.

In these figures, 1 is a platen around which the recording paper is wound, 2 is a carriage that is movable along this platen 1, that is, in a direction perpendicular to the paper plane of FIGS. The main shaft is arranged so as to penetrate through the main shaft and has an oval-shaped cross section. 4 is a head, 5 is a head mounting base that holds this head 4, and includes a head holding part 6 to which the head 4 is mounted, a gear part 7 in which a gear is formed, and an overhang part 8 extending to the bottom part. It is attached to the main shaft 3 so as to be rotatable integrally with the main shaft 3 and movable together with the carriage 2 in the axial direction of the main shaft 3. 9
is a lever integrated into this head mounting base 5,
A protrusion 10 is provided at the tip. Reference numeral 11 denotes a movable body, such as a rack, which is movable in the left-right direction of the paper surface of FIGS. 1 to 3 by the force of a driving source such as a motor, and has a groove 12 in the center of which the protrusion 10 of the lever 9 engages so as to be relatively movable. The groove 12 is made up of three parts at different heights, namely a lower part 13, a middle part 14, and an upper part 15. Reference numeral 16 denotes a cam rotatably provided on the carriage 2, which is capable of engaging with the protruding portion 8 of the head mounting base 4, and has a flat top portion 17a and a bottom portion 17b on the side surface. A gear means, for example a gear 18, which engages with the gear portion 7 of the head mount 5 mentioned above is provided at its rotation center. Reference numeral 19 denotes an elastic means, such as a spring, which urges the cam 16 and the head mount 5 to engage with each other, and has one end engaged with the carriage and the other end engaged with the overhang 8 of the head mount 5. There is.

By means of the above-mentioned rack 11, lever 9 having protrusion 10, head mounting base 5 having head holding part 6, gear part 7 and overhang part 8, cam 16 having high part 17a, bottom part 17b and gear 18, and spring 19. A head up-down device is configured.

The operation of the embodiment configured in this way is as follows.

That is, as shown in FIG. 1, when the rack 11 is moved to a state where the protrusion 10 of the lever 9 is located in the lower part 13 of the groove 12 of the rack 11, the force of the spring 19 prevents the head from being attached. The overhanging part 8 of the stand 5 has play with the bottom part 17b of the cam 16, and the cam 16 and the overhanging part 8 of the head mounting base 5 are brought into contact with each other and separated, resulting in a head-down state in which the head 4 is pressed against the platen 1. In this state, the head 4 is heated to transfer ink from an ink ribbon (not shown) placed between the recording paper and the head 4 onto a recording paper (not shown) located between the platen 1 and the head 4. As a result, it is possible to carry out melt transfer, and desired printing can be performed in accordance with the movement of the carriage 2.

Furthermore, when the rack 11 is moved in the direction of arrow 20 from the state shown in FIG. 1, as shown in FIG.
The protrusion 10 of the lever 9 is positioned in the upper part 15 of the groove 12, and accordingly the head mounting base 5 rotates against the force of the spring 19, and the head 4 separates from the platen 1. During this time, the gear portion 7 moves with the rotation of the head mounting base 5, which causes the gear 18 of the cam 16 to rotate, and the cam 16 to rotate integrally. In this state, the cam 16 and the projecting portion 8 of the head mounting base 5 are separated from each other.

Then, when the rack 11 is further moved in the direction of the arrow 21 from the state shown in FIG. After rotating in a direction approaching the platen 1, the head 4 stops, thereby moving the head 4 away from the platen 1 into a head-up state. In this state, the overhanging portion 8 of the head mounting base 5 is moved toward the cam 1 by the force of the spring 19.
The cam 16 and the head mounting base 5 are mechanically locked by engaging with the flat high portion 17a of the head 6, that is, by engaging the flat portions with each other, the cam 16 and the head mounting base 5 are in a stable head-up state, and the recording paper (not shown) is fed. , move the carriage to the home position, move the tab, etc.

In addition, in the state shown in FIG. 2 above,
As shown in FIG. 4, the teeth of the gear portion 7 of the head mount 5 are engaged with the teeth of the gear 18 of the cam 16, but in the state shown in FIG. As such, the teeth of the gear 18 of the cam 16 are positioned between the teeth of the gear portion 7 of the head mounting base 5, that is, a play is set between the teeth of the gear portion 7 and the gear 18. Therefore, when moving from the state shown in FIG. 3 to the state shown in FIG. Flat high part 17a
are pressed together and the head is locked in the open position.
Note that when the rack 11 moves to the right in FIG. 3, the height position of the protrusion 10 of the lever 9 remains constant, so that the head can be stably maintained in the up state regardless of the movement of the rack 11. .

In the embodiment configured in this way, the head can be raised and lowered well, and the head can be stably maintained in the head-up state without the need for a solenoid. Since the cam 16 and the like can be manufactured at low cost, manufacturing costs can be reduced.

[Effect of idea]

Since the head up-down device of the present invention is configured as described above, it can bring the head up without requiring a solenoid or the like as in the past, and has the effect of lowering manufacturing costs compared to the past. There is.

[Brief explanation of the drawing]

Figures 1 to 3 are explanatory diagrams showing one embodiment of the head up-down device of the present invention. Figure 1 is a sectional side view of the main part showing the head down state, and Figure 2 is the mutual relationship between the head down and the head up. Fig. 3 is a side sectional view of the main part showing the transition state of the head, Fig. 4 is an enlarged view of the engagement relationship between the cam and the head mounting base shown in Fig. 2. The explanatory diagram, FIG. 5, is an explanatory diagram showing an enlarged view of the engagement relationship between the cam and the head mounting base shown in FIG. 3. 1...Platen, 2...Carriage, 3...Main shaft, 4...Head, 5...Head mounting base, 6...Head holding part, 7...Gear part, 8...
Overhanging portion, 9...Lever, 10...Protrusion, 11...
...Rack (moving body), 12...Groove, 13...Lower section, 14...Middle section, 15...Upper section, 16...
Cam, 17a...Top part, 17b...Bottom part, 18...
...Gear, 19...Spring (elastic member).

Claims (1)

[Scope of utility model registration request] head, a head mount that holds this head,
and a head up-down device, which is provided in a thermal printer having a carriage in which the head mounting base is disposed, and which lowers the head in a direction toward the platen and raises the head in a direction away from the platen according to the movement of the moving body. In the apparatus, the head mount is rotatably provided on the carriage, the head mount is provided with a gear portion, and the head mount is provided with a gear means that engages with the gear portion and is engageable with the head mount. A head up-down device, characterized in that a cam is rotatably mounted on the carriage, and an elastic member is provided for biasing the cam and the head mount to engage with each other.