JPS631429Y2 - - Google Patents

Description

[Detailed explanation of the idea] (Technical field) The present invention relates to a sheet heating element.

(Background Art) Conventionally, as shown in FIG. 2, an organic semiconductor 1' having negative temperature-impedance characteristics such as nylon has been used.
A planar heating element is widely used in which a heater electrode 2' and a heat-sensitive electrode 3' are arranged side by side on the front surface, a reflective electrode 4' is arranged on the back surface, and the front and back sides are covered with an insulating film 5'.

In the case of this planar heating element, a temperature detection resistor is used to detect the decrease in the impedance of the organic semiconductor 1' between the heater electrode 2' and the heat-sensitive electrode 3' via the reflective electrode 4' due to the temperature rise. The temperature is controlled by detecting an increase in the flowing current and operating a relay or the like in response to this to control the current supply to the heater electrode 2'.

Here, the impedance distribution of such a conventional example is equivalently shown in FIG. 3, where the impedance under the heater electrode 2' |Z _H | and the impedance under the heat-sensitive electrode 3' |Z _S | Since the temperature is controlled by the total impedance |Z _T |=|Z _H |+|Z _S |, the impedance |Z _S | of the heat-sensitive electrode 3', which does not generate heat, has a great influence on temperature control. In other words, the impedance |Z _H | under the heater electrode 2' is directly affected by the temperature rise, so the impedance value decreases and acts to promote a predetermined temperature control, but the impedance under the heat-sensitive electrode 3' |Z _S Since | is not directly affected by the temperature of the heater electrode 2', its temperature does not rise much, and its impedance value does not fall much.
Therefore, the total impedance |Z _T | exceeds the expected value as a whole, in other words, the temperature below the heater electrode 2' falls below the target control temperature, and the sensitivity of the heat-sensitive electrode 3' deteriorates. The situation had come to be.

This problem becomes more noticeable when a plurality of heater electrodes 2' are arranged in parallel and a plurality of heat-sensitive electrodes 3' are arranged in parallel between them as shown in FIG.

In addition, in the past, because the sensitivity of the heat-sensitive electrode 3' was poor, the temperature of the heater electrode 2' under the insulation material became extremely high when local insulation was performed using an insulation material such as a cushion.
This had the disadvantage of causing uneven temperature distribution in the planar heating element.

(Purpose of the invention) The present invention was proposed to eliminate the above-mentioned drawbacks, and the original purpose is to connect a single line of heat-sensitive electrodes between heater electrodes constituting a plurality of heater circuits. This arrangement reduces the temperature difference between the bottom of the heater electrode and the bottom of the heat-sensitive electrode, increasing the sensitivity of the heat-sensitive electrode, ensuring accurate and appropriate temperature control, and preventing uneven temperature distribution due to local overheating. An object of the present invention is to provide a planar heating element with a

(Disclosure of invention) The present invention will be explained below with reference to the drawings.

In FIG. 1, 1 is an organic semiconductor having negative temperature-impedance characteristics such as nylon, and on its surface, a first heater electrode 2a and a second heater electrode 2b forming two heater circuits are arranged in parallel. and a heat-sensitive electrode 3 between them.
Each track is placed in parallel with an appropriate distance between them. Further, a reflective electrode 4 is disposed on the back surface of the organic semiconductor 1 so as to span the first and second heater electrodes 2a, 2b and the heat-sensitive electrode 3 on the front surface.
Further, as shown in FIG. 1B, insulating films 5 are provided on the front and back sides, respectively.

In the present invention configured in this manner, all the heat-sensitive electrodes 3 are disposed between the heater electrodes 2a and 2b, so that the heat-sensitive electrode 3 has the first and second heater electrodes 2a on both sides thereof. , 2b is constantly transferred. Therefore, the temperature difference between the heater electrodes 2a and 2b and the heat-sensitive electrode ₃ is reduced as shown in FIG. can be performed accurately, and the temperature detection ability can be greatly improved.

(Effects of the invention) As explained above, according to the invention, a heater electrode and a heat-sensitive electrode are formed on the surface of an organic semiconductor, and changes in the impedance of the organic semiconductor between the heater electrode and the heat-sensitive electrode due to temperature changes can be detected. In the planar heating element in which energization to the heater electrodes is controlled by the heat-sensitive electrodes, each line of the heat-sensitive electrodes is disposed between the heater electrodes constituting a plurality of heater circuits. It is possible to increase the sensitivity of the heat-sensitive electrode by reducing the temperature difference between the heat-sensitive electrode and the bottom, which has the effect of realizing accurate and appropriate temperature control.

In addition, since there is no inconvenience such as the temperature under the heater electrode rising abnormally as in the conventional case, uneven temperature distribution due to local overheating can be prevented, and an almost uniform heating effect can be achieved over the entire area of the planar heating element. It has advantages such as:

[Brief explanation of the drawing]

Fig. 1 shows an embodiment of the present invention, in which Fig. 1A is an enlarged plan view of the main part, Fig. 1B is a sectional view taken along line A-A and temperature distribution diagram of Fig. 2A, and Figs. 2 to 4. shows a conventional example; Fig. 2 is an explanatory cross-sectional view of the main part;
The figure is an explanatory diagram showing the impedance distribution, Figure 4A is an enlarged plan view of the main part, and Figure 4B is B-B of Figure 4A.
They are a cross-sectional view and a temperature distribution diagram. 1... Organic semiconductor, 2a, 2b... Heater electrode, 3... Heat sensitive electrode.

Claims (1)

[Scope of utility model registration request] A sheet heating device in which a heater electrode and a heat-sensitive electrode are formed on the surface of an organic semiconductor, and a change in impedance of the organic semiconductor between the heater electrode and the heat-sensitive electrode due to a temperature change is detected to control energization to the heater electrode. 1. A planar heating element, wherein one line of the heat-sensitive electrodes is disposed between each of the heater electrodes constituting a plurality of heater circuits.