JPH028595B2 - - Google Patents

Description

[Detailed description of the invention] The present invention relates to impact dot printers.

The printing stylus of the printing head in an impact dot printer is driven by the excitation of an electromagnet. Therefore, when increasing the printing speed, an increase in the temperature of the printing head becomes a problem. By the way, in conventional impact dot printers, in order to suppress the rise in temperature of the print head, the printing speed is reduced when the print head reaches a certain temperature or higher, which prevents the printing speed from increasing. . It has also been considered to mount a cooling fan on the carriage to constantly cool the print head. However, with this method, the cooling fan is constantly driven, which causes problems such as increased noise, and the weight of the carriage increases, reducing the print head movement speed.To avoid this, high output is required. Possible problems include the need to use a carriage drive system.

The present invention was developed based on the above-mentioned circumstances, and its purpose is to reduce the temperature rise above the set temperature of the print head, reduce the printing speed and the movement speed of the print head, or cause large noise. An object of the present invention is to provide an impact dot printer capable of realizing high-speed printing by preventing such problems without causing problems.

A first embodiment of the present invention will be described below with reference to FIG.

1 in the figure is the printer main body, and the left and right end plates 1
Two carriage guide rails 2, 2 are installed between a and 1b, and a platen 3 is rotatably disposed behind these rails. Further, between the end plates 1a and 1b, behind the platen 3, there is a paper feed tractor 4 for positioning and feeding paper (not shown) in the left and right direction.
4 are arranged. Note that 5 indicates a knob. A carriage 6 is supported by the carriage guide rails 2, 2 so as to be movable along the axial direction thereof. The carriage 6 is reciprocated from side to side via a belt 9 guided by a pair of pulleys 8 (only one shown) by a pulse motor 7 that is driven and controlled by an external controller (not shown). This carriage 6 is equipped with a printing head 10 and an ink ribbon cartridge 11 for performing dot impact printing.
In the figure, reference numeral 12 denotes a ribbon drive pulley, which is rotated as the carriage 6 moves by a string (not shown) wound around the pulley and stretched between the end plates 1a and 1b. And print head 10
In this embodiment, printing is performed in one direction. One-way printing is a printing method in which printing is performed when the carriage 6 moves from the left end to the right, and no printing is performed when the carriage 6 returns to the left end after printing to the right end. On the other hand, a head cooling fan 13 is attached to the printer main body 1, and since unidirectional printing is performed in this embodiment, the head cooling fan 13 is placed opposite the position where the carriage 6 stops at the left end of the printer main body 1. is located at the bottom of the Further, a temperature detector 14 is attached to the print head 10 to detect its temperature. The output of this detector 14 is input to a drive control means, for example, a fan control device 15. The fan control device 15 has the print head 1 installed in advance.
The upper limit of the 0 temperature (temperature that does not interfere with printing) is set, and this set temperature is compared with the detected temperature from the temperature detector 14, and if the detected temperature exceeds the set temperature, the fan control device 15 is designed to output a fan drive signal. The head cooling fan 13 can be driven in response to a fan drive signal, but the fan is operated until the carriage 6 returns to the left end to face the head cooling fan 13 and starts the next printing. It is controlled by a control device 15 or the like.

Therefore, in this embodiment, the print head 10
The temperature of the print head 10 rises with high-speed printing. This temperature is detected by a temperature detector 14 and compared with a set temperature by a fan control device 15. As a result of this comparison, print head 1 is lower than the set temperature.
When the temperature at 0 is high, the fan control device 15 outputs a fan drive signal, so the head cooling fan 13 is driven until the carriage 6 returns to the left end and starts printing the next line. be done. In this manner, the print head 10 is air-cooled while facing the head cooling fan 13. This air cooling effect continues repeatedly until the temperature of the print head 10 falls below the set temperature.
At the same time when the temperature becomes lower than the set temperature, the drive of the head cooling fan 13 is also stopped.

Note that this embodiment may be modified as follows.
For example, in order to further improve the cooling effect of the print head, another head cooling fan may be disposed at the right end where the carriage 6 starts returning. and,
For the same reason, the printing method is bidirectional printing, that is,
In a printing system that prints not only when the carriage 6 moves from the left end to the right, but also when it moves from the right end to the left during return, a pair of head cooling fans are placed at the left and right ends where the carriage 6 stops, respectively. It's okay. In addition, when a pair of head cooling fans is provided in this way, the fan control device 1
5 controls the head cooling fan in the direction of movement of the carriage 6 to be driven when necessary. Furthermore, the head cooling fan 13 may be disposed not only at the left and right ends but also at an intermediate location between these ends.

Next, in explaining the second embodiment shown in FIG. 2, the same structural parts as in the first embodiment will be given the same reference numerals as those in the first embodiment, and the explanation thereof will be omitted, and the different structural parts will be explained. I will only explain about.

That is, the head cooling fan 13 cools the print head 10 on the end plate 1b of the printer body 1, for example.
The printing head 10 is mounted on an extension line in the moving direction of the printing head 10 so as to be able to blow air toward the printing head 10. When the detected temperature becomes higher than the set temperature, the fan control device 15 immediately controls the drive of the head cooling fan 13 for a predetermined period of time or until the temperature of the print head 10 drops to a temperature lower than the set temperature. ing.

Therefore, in this embodiment, the print head 10 is
The head cooling fan 13 and the head cooling fan 13 are opposed to each other, and this state does not change regardless of the movement of the carriage 6. Therefore, as soon as the print head 10 reaches the set temperature, the head cooling fan 13 is driven and the print head 10 is air-cooled. Ru.

Note that in this embodiment, the head cooling fan 1
3 may be attached to the end plate 1a of the printer main body 1. Further, in order to further improve the cooling effect of the print head, head cooling fans 13 may be attached to each of the end plates 1a and 1b. In this case, the fan control device 15 drives and controls the left and right head cooling fans simultaneously.

Each of the above-mentioned embodiments is constructed as described above, but in carrying out the present invention, the printer main body, carriage, print head, head cooling fan, temperature detector, drive control means, etc. It goes without saying that the specific structure, shape, position, etc. are not limited to the above embodiments, and can be implemented in various configurations.

As explained above, according to the present invention, a head cooling fan is attached to the printer body and the print head is air-cooled by this fan, so that it is possible to prevent the temperature of the print head from increasing due to high-speed printing. Furthermore, since the head cooling fan is not provided in the carriage but in the printer body, there is no need for a reduction in the moving speed of the print head or for a large output carriage drive system to compensate for this. The head cooling fan is driven by detecting the set temperature of the temperature sensor attached to the print head, with the print head and the head cooling fan facing each other, so that the print head is air-cooled only when necessary. In addition, since it is not necessary to constantly drive the head cooling fan, it is possible to reduce the amount of noise emitted.

[Brief explanation of drawings]

FIG. 1 is a perspective view showing a first embodiment of the invention, and FIG. 2 is a perspective view showing a second embodiment of the invention. 1... Printer body, 6... Carriage, 10
...Print head, 13...Head cooling fan, 1
4... Temperature detector, 15... Fan control device.

Claims (1)

[Claims] 1. A printing head mounted on a carriage,
This impact dot printer that prints as the carriage moves from side to side includes: a temperature detector attached to the print head and outputting a signal when the temperature of the print head rises above a predetermined temperature; a cooling fan; cooling fan drive control means for driving the cooling fan to cool the printing head only when the printing head moves to a position facing the cooling fan during printing operation according to an output signal of the temperature detector; An impact dot printer characterized by: