JP2520703Y2 - Thermal head preheating device - Google Patents

Description

The present invention relates to a preheating device for a thermal head.

2. Description of the Related Art Conventionally, various things have been devised as to preheating a thermal head. For example, the first conventional example is disclosed in Japanese Patent Laid-Open No. 59-61273. This is to control the temperature of the heating element by changing the power supplied to the heating element arranged in the thermal head according to the signal state of the input pixel data. In this way, by preheating the thermal head and keeping the temperature higher than the room temperature, it is possible to perform high-speed printing with high quality.

A second conventional example is disclosed in JP-A-59-138476. This is because in a thermal printer that performs printing by energizing a heating element, the current for preheating the heating element is supplied in synchronization with the clock pulse used for printing operation, and the current supply time It is designed to be variable according to the change in the ambient temperature of the head. By thus supplying the current for preheating the heating element, it is possible to always keep the print density constant without requiring an additional circuit.

Further, as a third conventional example thereof, Japanese Patent Laid-Open No. 59-192585.
No. 6,086,045. In this, a heater for preheating is separately provided as a means for warming the thermal head. By separately providing a heater and performing preheating in this way, it is possible to keep the thermal head at a constant temperature and stabilize the operation.

DISCLOSURE OF THE INVENTION Problem to be Solved by the Invention As in the first and second conventional examples as described above, in the method of preheating by heating the heat generating element of the thermal head, the heat generating element is not insulated from the surroundings. Since the entire head must be heated, extra power is consumed, and it takes a long time for the temperature to rise, resulting in poor work efficiency.

In addition, in the method of separately providing a heater for preheating as in the third conventional example, the entire thermal head is warmed due to its overall structure, and thus in this case as well, loss of power consumption and work efficiency are achieved. Badness becomes a problem.

Means for Solving the Problems A heater, a heat pipe that is embedded in the thermal head in the vicinity of a heating element that is connected to the heater and that has a heating portion that is partially exposed to the outside, and a heat pipe. A heat transfer member provided so as to be joined to the pipe and the heat generating element, and a side that partially releases the side facing the heat generating element and covers the periphery of the heat transfer member, the heater, and the heat pipe to provide thermal. A heat insulating member embedded inside the head is provided. Further, the heater section is provided with a self-temperature control means.

Therefore, by providing the heat insulating member, it is possible to insulate all of the heat transfer system including the heater, the heat pipe, and the heat transfer member except for the heat generating element serving as the printing portion, so that the heat loss is reduced as compared with the conventional case. Can be significantly reduced,
As a result, the power consumption can be made extremely small, and it is possible to eliminate thermal adverse effects on parts other than the thermal head section.

In addition, since the heater section is provided with the self-temperature control means, it is not necessary to separately provide a control circuit, so that the entire configuration can be simplified, and moreover, there is no fear of overheating and the reliability is high. It is possible to obtain the device.

An embodiment of the present invention will be described with reference to the drawings. Inside the thermal head 1, a heater 3 connected to a heater power supply 2 is provided. The heater 3 is provided with a self-temperature control unit (not shown), and is made of a flexible material as its material in consideration of the adhesiveness with other members. A heat pipe 4 for transmitting the heat generated from the heater 3 is connected to the heater 3, and a heat transfer member 5 is attached to the outer surface of the heat pipe 4.
Then, the heater 3, the heat pipe 4, and the heat transfer member 5
The heat insulating member 6 is provided so as to cover the periphery of the heat insulating member 6, and the heat insulating member 6 is embedded in the thermal head 1. Further, a part of the heat generating element 7 is arranged close to the heat pipe 4, and the heat generating portion of the heat generating element 7 is located on the upper surface of the thermal head 1 and is mounted so as to be exposed to the outside.

In such a configuration, the heat generated by the heater 3 driven by the heater power supply 2 vaporizes the heat medium (not shown) in the heat pipe 4. Then, the steam thus obtained advances in the heat pipe 4 at a speed close to the speed of sound and carries heat to the position of the heat generating element 7, thereby preheating the heat generating element 7. At this time, heat is released in the vicinity of the heating element 7 to become a liquid, which is returned to the heater 3 by a capillary phenomenon. And the heater 3
This series of operations is repeated until the temperature in the vicinity of the heat generating element 7 and the temperature in the vicinity of the heat generating element 7 become substantially the same, thereby completing the preheating operation.

The heat transfer system (heater 3, heat pipe 4,
In the thermal head having a structure in which the heat transfer member 5) is covered by the heat insulating member 6, since only the heat generating portion on the surface of the heat generating element 7 is exposed to the outside air, the heat is higher than the conventional one. Can significantly reduce the loss,
As a result, the power consumption can be made extremely small, and since the excess heat is not transferred to the other parts of the thermal head, the peripheral devices are not adversely affected by heat.

Further, since the heater 3 is provided with the self-temperature control means, it is not necessary to separately provide a thermal control circuit (not shown), and furthermore, there is no fear of overheating of the heating element portion, and the reliability is high. It is possible to obtain the device. In this case, as the self-temperature control means, for example, a temperature sensor (not shown) may be arranged in the vicinity of the heater 3 or the heat-generating element 7 capable of preheating to a constant temperature to perform known proportional control.

Furthermore, by constructing the entire heat transfer system integrally with the thermal head, the overall configuration can be further simplified.

Effect of the Invention As described above, the present invention is a heat pipe embedded in the thermal head in the vicinity of a heater and a heating element that is connected to the heater and has a heating portion that is partially exposed to the outside. And a heat transfer member provided so as to be joined to the heat pipe and the heat generating element, and a side of the heat transfer member, the heater, and the heat pipe that partially opens the side facing the heat generating element. And a heat insulating member embedded inside the thermal head. Further, since the heater section is provided with the self-temperature control means, the heat insulating member can insulate the entire heat transfer system including the heater, the heat pipe, and the heat transfer member except the heat generating element serving as the printing section. The thermal loss can be greatly reduced as compared with the conventional one, and thereby, the power consumption can be made extremely small and the thermal adverse effects on the parts other than the thermal head part can be eliminated.

Further, since the heater section is provided with the self-temperature control means, it is not necessary to separately provide a thermal control circuit, so that the entire configuration can be simplified, and moreover, since there is no fear of overheating, reliability is improved. It is possible to obtain a device with higher performance.

[Brief description of drawings]

FIG. 1 is a vertical side view showing an embodiment of the present invention, and FIG. 2 is a vertical side view seen from the AA side. 1 ... Thermal head, 3 ... Heater, 4 ... Heat pipe, 5 ... Heat transfer member, 6 ... Heat insulating member, 7 ... Heating element

Claims (2)

(57) [Scope of utility model registration request] 1. A heat pipe, a heat pipe which is embedded in the thermal head in the vicinity of a heat generating element that is connected to the heater and has a heat generating portion partially exposed to the outside, and the heat pipe. Inside the thermal head, the heat transfer member provided to be joined to the heat generating element and the side facing the heat generating element are partially opened and the periphery of the heat transfer member, the heater and the heat pipe are covered. A preheating device for a thermal head, characterized in that it comprises a heat insulating member buried in. 2. A preheating device for a thermal head according to claim 1, wherein the heater portion is provided with self-temperature control means.