JPH0545987U - Sheet heating element - Google Patents

Abstract

(57) [Summary] [Purpose] The structure is simple and easy to manufacture. A planar heating element 1 in which a resistance heating element 5 is provided between a pair of electrodes 3 and 3'wherein the resistance heating element is a PTC material having a positive temperature coefficient, that is, resistance increases with increasing temperature. A resistance material whose value increases and the resistance value sharply increases at a predetermined temperature is applied on the substrate 2 on which the electrodes are formed.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a novel sheet heating element. More specifically, the present invention aims to provide a novel sheet heating element having a simple structure and easily manufactured.

[0002]

[Prior Art]

 Sheet heating elements are widely used. For example, in a mirror provided outside the vehicle such as a door mirror or a fender mirror, even if fog occurs during driving, it is not possible to wipe the mirror surface to remove the fog, so warm it. It is known that a sheet heating element is attached to the rear surface of the mirror to remove the fogging, and the sheet heating element is energized to generate heat to remove the fogging of the mirror.

In such a sheet heating element, a circuit is formed by a resistance heating element on a substrate, and the circuit is heated by passing a current through the circuit.

By the way, such a planar heating element has various dangers when its temperature becomes infinitely high. Therefore, the conventional planar heating element a has, for example, a structure as shown in FIG. Was there.

That is, the resistance heating element c is formed on the substrate b so as to crawl on the substrate b evenly, and a thermostat d is inserted in the middle of the resistance heating element c so that the temperature becomes higher than a certain temperature. I was trying to prevent this.

[0006]

[Problems to be solved by the device]

 In the above-described conventional sheet heating element a, it is necessary to form the resistance heating element c on the substrate b in a predetermined pattern. Therefore, for example, a paste-shaped resistance heating material is screen-printed on the substrate b. There is a problem that it is troublesome to manufacture it because it is necessary to take a means such as applying it on top.

In addition, it is necessary to attach a thermostat so that the temperature does not rise above a predetermined temperature, which increases the number of extra steps and increases the cost, and the shape is bulky. However, it has also been a cause of hindering the miniaturization or thinning of devices.

[0008]

[Means for Solving the Problems]

 The planar heating element of the present invention is a planar heating element in which a resistance heating element is provided between a pair of electrodes in order to solve the above problems, and the resistance heating element has a positive temperature coefficient. A material, that is, a resistance material whose resistance value increases with increasing temperature and whose resistance value sharply increases at a predetermined temperature is applied on a substrate on which electrodes are formed.

[0009]

[Action]

 Therefore, in the planar heating element of the present invention, the resistance heating element may be formed by applying the PTC material having a positive temperature coefficient to one surface of the substrate having the electrode, which contributes to cost reduction. .

Further, since the resistance heating element itself has a temperature control function, it is not necessary to provide a special part such as a thermostat for temperature control, and in this respect also, the manufacturing process is simplified, Furthermore, it can be made into a clean shape without any unevenness, which contributes to downsizing and thinning of a device using this sheet heating element.

Furthermore, if the substrate is made of a flexible material, it is possible to apply the planar heating element in a wide range without any problem even if the planar heating element is provided with irregularities or bends. it can.

[0012]

【Example】

 The sheet heating element of the present invention will be described in detail below with reference to Example 1 shown in the accompanying drawings.

Reference numeral 2 denotes a flexible insulating substrate, which is formed of, for example, a polyester film.

On the substrate 2, electrodes 3 and 3 ′ made of metal foil are formed. The electrodes 3 and 3 ′ each have a comb shape, and the comb tooth portions 4, 4, ... And 4 ′ and 4 ′ are located alternately, that is, the combs of one electrode 3 are arranged. The tooth portions 4, 4, ... Are formed so as to be positioned at a predetermined interval between the comb tooth portions 4 ', 4', ... Of the other electrode 3 '.

The electrodes 3 and 3 ′ can be formed by a method such as plating the substrate 2 with copper.

Reference numeral 5 is a resistance heating element, which is formed on the surface of the substrate 2 on which the electrodes 3 and 3 ′ are formed. Therefore, the resistance heating element 5 is located between the electrodes 3 and 3 ′, and when the electrodes 3 and 3 ′ are connected to the power source 6, the resistance heating element 5 generates heat.

The resistance heating element 5 is a PTC material having a positive temperature coefficient, that is, a resistance material whose resistance value increases with a rise in temperature and which sharply rises at a predetermined temperature, such as acetic acid. It is formed by applying a vinyl-based PTC material to the entire surface of the substrate 2 on which the electrodes 3 and 3'are formed.

The planar heating element 1 as described above has no protrusion and is flexible.

Then, such a sheet heating element 1 is attached to the back surface of the mirror 9 of the door mirror for an automobile by bonding or the like.

[0020]

[Effect of the device]

 As is clear from the above description, the planar heating element of the present invention is a planar heating element in which a resistance heating element is provided between a pair of electrodes, and the resistance heating element has a positive temperature coefficient. The present invention is characterized in that a PTC material included therein, that is, a resistance material whose resistance value increases with increasing temperature and whose resistance value sharply increases at a predetermined temperature is applied onto a substrate on which electrodes are formed.

Therefore, in the planar heating element of the present invention, the resistance heating element may be formed by applying the PTC material having a positive temperature coefficient to one surface of the substrate having the electrodes, which reduces the cost. Contribute to.

Further, since the resistance heating element itself has a temperature control function, it is not necessary to provide a special part such as a thermostat for temperature control, and in this respect also, the manufacturing process is simplified, Furthermore, it can be made into a clean shape without any unevenness, which contributes to downsizing and thinning of a device using this sheet heating element.

In addition, the planar heating element of the present invention has two electrodes having a comb shape on a flexible insulating substrate, and the comb teeth of one electrode are placed between the comb teeth of the other electrode. It is formed in combination so as to be positioned at intervals, and a resistance heating element is applied to the surface of the flexible substrate having the electrodes on the side where the electrodes are formed.

Therefore, according to the present invention, even if the area where the sheet heating element is provided has irregularities or bends, the application range of the sheet heating element is widened.

It should be noted that the specific shapes and structures shown in the above-mentioned embodiments are merely examples for embodying the present invention, and the technical scope of the present invention is limitedly interpreted by these. It is not something that will be done.

[Brief description of drawings]

FIG. 1 is a perspective view showing an example of implementation of the planar heating element of the present invention.

FIG. 2 is a perspective view showing a substrate having electrodes and a resistance heating element separately.

FIG. 3 is a cross-sectional view showing an enlarged main part.

FIG. 4 is a perspective view of a main part showing an example of a usage mode.

FIG. 5 is a perspective view showing an example of a conventional sheet heating element.

[Explanation of symbols]

 1 planar heating element 2 substrate 3, 3'electrode 4, 4'comb tooth portion 5 resistance heating element

Claims (2)

[Scope of utility model registration request] 1. A planar heating element in which a resistance heating element is provided between a pair of electrodes, wherein the resistance heating element is a PTC material having a positive temperature coefficient, that is, the resistance value increases as the temperature rises. A planar heating element, characterized in that a resistance material whose resistance value sharply rises at a predetermined temperature is applied onto a substrate on which electrodes are formed. 2. A pair of comb-shaped electrodes is formed on a flexible insulating substrate so that the comb-teeth portion of one electrode is spaced from the comb-teeth portion of the other electrode. The planar heating element according to claim 1, wherein the heating element is formed by combining the electrodes, and a resistance heating element is applied to the surface of the flexible substrate having the electrodes on the side where the electrodes are formed.