JPH0378273B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Technical Field) The present invention relates to a so-called serial type thermal printer equipped with a cassette for storing an ink ribbon for thermal transfer.

(Prior Art) The schematic structure of a conventional thermal printer of this type can be shown in FIGS. 1 to 3. In these figures, reference numeral 1 denotes a platen, and a recording paper 3 is pressed against the platen 1 by a paper presser 2. As shown in FIG. 4
is a cassette in which a thermal transfer ink ribbon 5 is stored, and there is a rectangular notch 6 in the center of the end on the platen 1 side.
is provided. The ink ribbon 5 is exposed to the outside at this cutout portion. Also, one end of the ink ribbon 5 is connected to a take-up roller 7, and the other end is connected to a delivery roller 8.
are fixed to each. The take-up roller 7 is manually rotated by a knob 19 as necessary, and
During the forward stroke of the printing operation (when moving in the right direction in FIGS. 1 and 3), it is rotated by the drive shaft 9. Reference numeral 10 denotes a cassette holder, which is fixed to the carriage 11. The loading of the cassette 4 into the cassette holder 10 is carried out using the positioning pin 12.
done with the help of Said carriage 1
1 is guided by a guide shaft 13 and moves in the lateral direction in FIGS. 1 and 3, and its drive is as follows:
A belt 16 is wound between the driving pulley 14 and the driven pulley 15 and is locked to the carriage 11.
This is performed by moving the motor 17 via the drive pulley 14. A thermal head 18 is disposed in a space between the notch 6 of the cassette 4 and the ink ribbon 5, and its lower part is pivotally connected to the carriage 11 so as to be tiltable.
Although not shown, the thermal head 18 is always urged by a spring in the direction away from the ink ribbon 5 (that is, it is urged so as to maintain the position shown in FIG. 2), and during the forward stroke of the printing operation. (1st
3), the ink ribbon 5 side is forcibly tilted using a solenoid, etc., and the back side of the ink ribbon 5 (the side on which ink is not applied) is moved to the heating element part. While pressing with
The recording paper 3 is pressed against the platen 1 to bring the surface of the ink ribbon 5 into contact with the recording paper 3.
Further, 20 is a felt rod, and 21 is a felt plate, which are in contact with both sides of the ink ribbon 5 using the elastic force of a leaf spring 22. Therefore, dust and the like attached to the ink ribbon 5 are removed here.

In recording with a thermal printer in such a configuration, the carriage 11 is moved in the lateral direction in FIGS. 1 and 3, and the platen 1 is intermittently driven in the direction of the arrow in FIG. 1 for each horizontal printing. It is done by In addition, during the backward stroke of the printing operation (when moving to the left in Figures 1 and 3), the thermal head 1
8 is away from the ink ribbon 5, and thermal transfer is not performed.

Incidentally, in serial type thermal printers, there is a demand for increased printing speed, and efforts are being made to make the base of the ink ribbon 5 thinner. However, due to this thinning, the recording paper 3
Even if an attempt was made to remove the ink ribbon 5 from the ink ribbon, it could not be removed successfully, resulting in a problem in that the print quality deteriorated. According to experiments conducted by the present inventor, it was found that this problem could be solved by increasing the peeling angle θ (see Figure 3). Since the notch 6 for inserting the thermal head 18 is provided in the center of the end, it is difficult to make the peeling angle θ large due to the structure, and if you try to make it too large, it will put a lot of tension on the ink ribbon 5. Therefore, there is a problem that the ink ribbon breaks during the printing operation due to the thinning of the base.

Furthermore, in conventional thermal printers, the thermal head 1 is attached to the ink ribbon 5 when loading the cassette.
In some cases, the ink ribbon 8 collides with the ink ribbon 5, making it impossible to load the ink ribbon accurately or damaging the ink ribbon 5.

(Object of the Invention) The present invention has been made in view of the above points, and its purpose is to realize a serial type thermal printer that has excellent printing quality, can load the cassette accurately, and can avoid damage to the ink ribbon. It's about doing.

(Structure of the Invention) The structure of the present invention that achieves this object consists of a cassette which stores an ink ribbon for thermal transfer inside, has a notch for inserting a thermal head near its corner, and a cassette which is tilted to the head support part of the carriage. a thermal head which is freely pivotally mounted and whose heating element portion is located in a space near the notch of the cassette so as to be able to come into contact with the ink ribbon; a cassette holder which is attached to the carriage and into which the cassette is loaded; , a hinge pin for horizontally rotatably attaching at least one of the head support portion of the carriage or the cassette holder to the carriage body.

(Example) Hereinafter, an example of the present invention will be described with reference to the drawings.

FIG. 4 is a partially cutaway plan view showing the main parts of an embodiment of the present invention. In this figure, parts corresponding to those in FIGS. 1 to 3 are designated by the same reference numerals, and their explanations will be omitted. The first difference between this embodiment and the thermal printer shown in FIGS. 1 to 3 is that a notch 6 is provided at the corner of the cassette 4 through which the thermal head 18 is inserted, and the notch 6 and the ink ribbon are connected to each other. 5
The thermal head 18 is placed in the space between the printer and printer, and during the forward stroke of the printing operation, the thermal head 18 is moved (tilted) toward the platen as shown in FIG.
This is because the ink ribbon 5 is configured so as to be brought into contact with the ink ribbon 5.

If the notch 6 is formed at this position, the ink ribbon 5 will be exposed outside the cassette 4 at the corner of the cassette 4 where the ink ribbon 5 bends as it is wound around the take-up roller 7. Therefore, the peeling angle θ can be easily set to a large value. Therefore,
Print quality can be improved. Further, by adopting this configuration, it is possible to easily move the thermal head 18 to the edge of the recording paper 3, and it is also possible to obtain the effect that printing can be performed up to the edge of the recording paper 3.

The second difference between this embodiment and the conventional example is that
This becomes clear when comparing Figures 2 and 5. FIG. 5 is a partial sectional view corresponding to the main part seen from the left side of FIG. 4. In this example, carriage 1
One head support section is configured to be horizontally rotatable. That is, a rotating block 31 that can be horizontally rotated around a hinge pin (hereinafter referred to as pin) 30 is used as a head supporter, and this is used as a head supporter for the carriage 11.
It is pivoted to the main body. Further, the thermal head 18 is pivotally attached to the rotation block 31 using a pin 35 so as to be tiltable. Therefore, the thermal head 18 can not only tilt about the pin 35 in the direction of the arrow in FIG. 5 with respect to the main body of the carriage 11, but also horizontally rotate about the pin 30. In this regard, in the conventional configuration, the head support portion was formed integrally with the main body of the carriage 11, and the thermal head 18 could only be tilted relative to the main body of the carriage 11. The carriage 11 is formed with an arcuate groove 11a centered on the pin 30, and the thermal head 18 can be moved between the printing standby position shown in FIG. 6B and the printing state position shown in FIG. The rotational position of the rotary block 31 is the same in each position) and the position rotated 90 degrees from the above position (see Fig. 6A) is set at a predetermined position of the arcuate groove 11a. A deep hole is formed in which the steel ball 33 pressed toward the arcuate groove 11a by the coil spring 32 is deeply fitted.

With this configuration, the cassette 4 can be loaded when the thermal head 18 is in the state shown in FIG. 6A, so that the ink ribbon 5 does not come into contact with the thermal head 18. After loading the cassette 4, the thermal head 18 is rotated in the direction of the arrow in FIG. 6A to obtain the position shown in FIG. 6B.
Thereafter, printing can be performed by moving the thermal head 18 to the position shown in FIG. 6C as usual. The reason why loading in the state shown in Fig. 6A is easy is because the 6th position of the cassette 4
This is because there are no obstacles such as the platen 1 in the horizontal direction of the figure. Incidentally, reference numeral 23 in FIG. 4 is a reflective photo sensor for detecting the end of feeding of the ink ribbon 5, and is fixed to the carriage 11 side. This end detection sensor does not need to be a reflective type photo sensor as described above, but may be a conventionally widely used transmission type photo sensor or the like.

FIG. 7 is a partial sectional view showing another embodiment of the present invention, in which the cassette 4 is made rotatable. The rotation mechanism is exactly the same as that shown in FIG. 5, so a description thereof will be omitted. According to this configuration, as shown in FIG.
The cassette 4 can be rotated 90 degrees from the state shown in FIG. 8A to the state shown in FIG. By rotating the cassette 4 approximately 45° to the state shown in (b), printing and a printing standby state can be obtained. Needless to say, loading the cassette 4 becomes easier in these cases as well.

In the above description, the case where either the thermal head 18 or the cassette 4 is rotated has been described, but both may be rotated. In addition to manual movement, it is also possible to provide a sensor for detecting the loading of the cassette 4 and to automatically shift to the print standby state using a motor, solenoid, or the like.

(Effects of the Invention) As explained above, the corners of the cassette are the places where the ink ribbon bends as it is wound around the take-up roller.
Even if the ink ribbon is exposed outside the cassette, the tension of the ink ribbon will not be particularly increased. Therefore, according to the present invention, the peeling angle θ can be increased without causing any stress on the structure, and the printing quality can be improved. can be improved. Further, by adopting this configuration, the thermal head can be easily moved to the edge of the recording paper, and printing can be performed to the edge of the recording paper. Furthermore, the cassette can be loaded accurately and the ink ribbon is not damaged.

[Brief explanation of drawings]

Fig. 1 is an explanatory diagram showing the main structure of a conventional example. Fig. 1 is a perspective view, Fig. 2 is a side view (showing the cassette lifted up), and Fig. 3 is a partially cutaway plan view. It is. 4 is a partially cutaway plan view showing a main part of an embodiment of the present invention, FIG. 5 is a partial cross-sectional view of the main part of the embodiment shown in FIG. 4, viewed from the side, and FIG. 5 is an explanatory diagram of the operation of the embodiment shown in FIG. 5, and FIGS. 7 to 9 are explanatory diagrams of other embodiments of the present invention. 1...Platen, 2...Paper presser, 3...Recording paper, 4...Cassette, 5...Ink ribbon, 6...
... Notch, 7 ... Take-up roller, 8 ... Delivery roller,
9... Drive shaft, 10... Cassette holder, 11...
...Carriage, 12...Positioning pin, 13...
Guide shaft, 16...belt, 18...thermal head, 30...pin, 31...rotating block, 32...coil spring, 33...steel ball.

Claims (1)

[Scope of Claims] 1. A cassette that stores an ink ribbon for thermal transfer inside and has a notch for inserting a thermal head near its corner, and a cassette that is pivotally mounted to a head support portion of a carriage so as to be tiltable, and that generates heat. The body portion includes: a thermal head located in a space near the notch of the cassette so as to be able to contact the ink ribbon; a cassette holder attached to the carriage and into which the cassette is loaded; A serial type thermal printer, comprising: a hinge pin for horizontally rotatably attaching at least one of the cassette holders to the cartridge main body.