JPH0554237B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Technical Field) The present invention relates to a planar heating element used in electric carpets and the like.

(Background Art) When an electric carpet or the like is constructed using a planar heating element, in normal use, when a cushion or the like is used on the electric carpet, it becomes locally insulated and may become partially overheated. In order to avoid such overheating, for example, patent application No. 60-82198
In this issue, as shown in the plan view in Figure 5A and the A-A sectional view in Figure 5B, the impedance between the heating wire h and the temperature detection line t is increased to reduce the heat generated by the sensor current. There is one in which a first dummy electrode _d1 is provided to prevent a temperature rise under the insulation material during local insulation. In the figure, f is a heat-sensitive film, and d _2a and d _2b are second dummy electrodes. That is, the heat radiation line h and the temperature detection line t
The impedance between the heating wire h and the second dummy electrode d ₁ and the second dummy electrode d _2a and d _2b is
between the second dummy electrode _d2a and the first dummy electrode _d2a .
The value becomes large because it is the sum of the impedances between the dummy electrodes _d1 , between the first dummy electrodes _d1 and the second dummy electrodes _d2b , and between the second dummy electrodes _d2b and the temperature detection line t.

However, when wiring the sheet heating element shown in Figure 5A, in order to avoid printing defects etc. during the manufacturing stage of the sheet heating element, In other words, the distance between wires in the direction parallel to the direction of arrow X shown in the figure.
W ₁ may be about 1 mm, but in cases where the wires intersect at right angles or angles, the distance W ₂ between the wires needs to be about 4 to 5 mm. For this reason, the pitch between the heating lines h, that is, the pitch P 1 when the heating lines h run parallel to the feeding direction, is compared to the pitch P ₁ when the heating lines h intersect at a certain angle to the feeding direction. Because the pitch of P ₂ becomes wider,
The heating line h in the part that is at a certain angle to the feeding direction is rougher than the heating line h in the part parallel to the feeding direction, which is the reason why the temperature in that part does not rise and causes uneven temperature distribution in the electric carpet. It was becoming.

(Objective of the Invention) The present invention has been proposed in view of the above points, and its purpose is to provide a planar heating element in which the pitch between heating wires is narrowed to reduce unevenness in temperature distribution. be.

(Disclosure of the Invention) An embodiment of the present invention will be described below with reference to the drawings.

FIGS. 1A and 1B are diagrams showing one embodiment of the present invention, and FIG. 1A is a plan view showing pattern wiring;
Figure B is a sectional view taken along line B--B in figure A. The pattern wiring shown in this figure has two circuits, circuit 1 and circuit 2, running in parallel. In these two circuits,
The first dummy electrode d 1 on the top a of the inner circuit 1 (most central part in the figure) is removed at the position d _1a , and the first dummy electrode d ₁ on the top part a of the inner circuit 1 (the large central part in the figure) is removed, and the first dummy electrode d
Remove the dummy electrode d ₁ at the position d _1b , wire the heating wire h to the removed part, and change the pitch P ₃ between the heating wires h at the shoulder b to the pitch P ₂ shown in Fig. 5.
decreased further. The difference between P ₃ and P ₂ in this case is the sum of the inter-wiring distance W ₂ and the line width d _W of the first dummy electrode d ₁ . In other words, the pitch between heating wires h decreases by W ₂ + d _W , and the amount of heat generated per unit area increases,
The temperature of that area increases, and the unevenness of temperature distribution can be improved. Note that the density of the heating wires h can be similarly increased at the top portion a, and the unevenness of temperature distribution can also be improved at this portion.

Note that not removing the first dummy electrodes at the top of the outer circuit 2 and the shoulder of the inner circuit 1 will be explained with reference to FIGS. 2 and 3. On the other hand, as shown in FIG. 2, when local heat insulation is performed on the planar heating element by the elongated heat insulator 3, a first dummy electrode _d1 is provided at the top c of the circuits 1 and 2. Otherwise, the temperature of the area covered by the heat insulating material 3 over the entire top part c cannot be detected, so there is a risk that the lower part of the heat insulating material 3 will become abnormally high temperature. On the other hand, in the case of the present invention shown in FIG. 3, even if local heat insulation is performed on the planar heating element by the heat insulator 3 similar to that shown in FIG.
The area where temperature cannot be detected is the range indicated by the top part d, and the temperature under the heat insulating part 3 will not become abnormally high.

Next, FIG. 4 is a plan view showing another embodiment of the present invention. In this embodiment, the decrease in the impedance signal to be detected at the top a of the circuit 1 is caused by the wrap between the heating wire h of the circuit 2 and the second dummy electrode _{d2a .}
dummy electrode d ₁ and second dummy electrode d _2a and d _2b
The overlap margins I ₂ and J ₂ with each, and the second
Lap between the dummy electrode _d2b and the temperature detection line t.
If K ₂ is wrapped in the same way as shown in Figure 1A, then H ₁ , I ₁ ,
It is made larger than J ₁ and K ₁ and the opposing area of each is widened so that a sufficient impedance signal can be obtained. Furthermore, the facing area of the shoulder portion b of the circuit 2 is similarly increased from that of the circuit 1. Through these corrections, it is possible to ensure the same temperature detection ability as in the past, and also to improve temperature distribution unevenness.

(Effects of the Invention) As explained above, according to the present invention, temperature distribution unevenness is reduced by removing the first dummy electrode and disposing at least one of the heating wire and the temperature detection wire. Also, since the area occupied by the first dummy electrode among the heating wires, first dummy electrodes, and temperature sensing wires on the same surface is reduced, more heating wires and temperature sensing wires can be wired, increasing the degree of freedom in pattern design. . Since there is a degree of freedom in pattern design in this way, the width of the heating wire and the temperature detection wire can be increased, so that the lifespan until disconnection is extended. In other words, wire breakage occurs especially when a crack occurs in the wire width direction and the crack crosses the wire width direction.
Since the wire width can be secured, the occurrence of cracks can be minimized and a long life can be achieved. Note that the wire width can be made wider, so if you want to wire the same length of wire and generate the same amount of heat as when the wire width is narrower, the wire width is wider than the one with the narrower wire width. Since it is possible to use a metal foil that is thinner than that of the previous method, it has the effect of reducing costs.

[Brief explanation of drawings]

1A and 1B are diagrams showing an embodiment of the present invention, in which 1A is a plan view, 2B is a sectional view taken along line B-B in 1A, and 2 and 3 are diagrams showing an embodiment of the present invention. 4 is a diagram showing another embodiment of the present invention; FIGS. 5A and 5B are diagrams showing a conventional sheet heating element; FIG. is A-A in A of the same figure.
FIG. 1, 2...Circuit, h...Heating wire, t...Temperature detection line, _d1 ...First dummy electrode, _d1a , _d1b ...First dummy electrode end, _d2a , _d2b ... ...Second dummy electrode, a...Top part, b...Shoulder part, _P1 , _P2 , _P3 ...
…Pituchi, H ₁ , H ₂ , I ₁ , I ₂ , J ₁ , J ₂ , K ₁ , K ₂ …
...Rap up.

Claims (1)

[Claims] 1. A heating line and a temperature sensing line are wired in parallel on one side of a thermosensitive film, a first dummy electrode is arranged between them, and a heating line and a temperature sensing line are placed on the other side of the thermal film. A second dummy electrode divided at a position opposite to the wire and opposite to the first dummy electrode is arranged, and the distance between the wires in the direction parallel to the feeding direction of the sheet heating element during printing is , in a planar heating element with a wide distance between wires that are wired at an angle rather than parallel to the feeding direction of the planar heating element during printing, the heating wire and the temperature detection wire are arranged in a zigzag pattern, and in multiple rows. Remove the first dummy electrodes that are wired at an angle that is not parallel to the feeding direction of the sheet heating element during printing at each top other than the top of the outermost circuit of the parallelly arranged patterns, and By arranging the heating wires closely together, the pitch between the heating wires, which are wired at an angle rather than parallel to the feeding direction of the planar heating element during printing, can be adjusted between the heating wires and the first dummy electrode. A planar heating element characterized in that the distance between the wiring lines is reduced by the sum of the line width of the first dummy electrode.