JP2023006588A - Planar heating element, optical device, and method for manufacturing planar heating element - Google Patents

Abstract

To provide a planar heating element, an optical device, and a method for manufacturing the planar heating element that can more easily achieve temperature control of a transparent electrode.SOLUTION: A planar heating element has an insulating sheet with a transparent electrode on the first side that generates heat when energized, a PTC (Positive Temperature Coefficient) element on the second side that is the back side of the first side and is connected in series with the transparent electrode, and a first and second electrode that are provided on the transparent electrode at a distance from each other. The transparent electrode includes a first region, a second region, and a third region that are electrically insulated with a groove having a depth equal to its thickness as a boundary. One end of the first electrode is provided in the first region, and the other end of the first electrode is provided in the third region. One end of the second electrode is provided in the second region and the other end of the second electrode is provided in the third region.SELECTED DRAWING: Figure 1

Description

TECHNICAL FIELD The present disclosure relates to planar heating elements, optical devices, and methods of manufacturing planar heating elements.

2. Description of the Related Art Conventionally, there has been known a planar heating element provided with a transparent electrode (which may be referred to as a transparent conductive film) that generates heat when energized. This planar heating element is attached to, for example, a glass window of an automobile, and the heat generated by the transparent electrode can suppress freezing and fogging of the glass window (see, for example, Patent Document 1).

Japanese Patent No. 6607123

However, conventionally, since the transparent electrode itself does not have a temperature control function, the temperature of the transparent electrode is controlled using a control device (for example, a thermistor, a thermostat, etc.) provided outside the planar heating element. I needed it.

An object of one aspect of the present disclosure is to provide a planar heating element, an optical device, and a manufacturing method of the planar heating element that can more easily control the temperature of the transparent electrode.

A planar heating element according to an aspect of the present disclosure includes an insulating sheet having a first surface provided with a transparent electrode that generates heat when energized, and a second surface that is the back surface of the first surface, and the transparent electrode A PTC (Positive Temperature Coefficient) element connected in series, and a first electrode and a second electrode spaced apart from each other on the transparent electrode, wherein the transparent electrode has a thickness including a first region, a second region, and a third region that are electrically insulated with grooves having the same depth as boundaries; one end of the first electrode is provided in the first region; The other end is provided in the third region, one end of the second electrode is provided in the second region, and the other end of the second electrode is provided in the third region.

An optical device according to one aspect of the present disclosure includes a planar heating element according to one aspect of the present disclosure.

A method for manufacturing a planar heating element according to an aspect of the present disclosure provides a transparent electrode that generates heat when energized on a first surface of an insulating sheet, and a positive temperature coefficient (PTC) on a second surface that is the back surface of the first surface. An element is provided, the PTC element and the transparent electrode are connected in series, and a groove having the same depth as the thickness of the transparent electrode is formed in the transparent electrode, thereby electrically connecting the groove with the boundary as a boundary. forming a first region, a second region, and a third region to be insulated, providing a first electrode and a second electrode spaced apart from each other on the transparent electrode, providing one end of the first electrode in the first region; The other end of the first electrode is provided in the third region, one end of the second electrode is provided in the second region, and the other end of the second electrode is provided in the third region.

According to the present disclosure, temperature control of the transparent electrode can be more easily achieved.

1 is an exploded perspective view of a planar heating element according to an embodiment of the present disclosure FIG. 2 is a front view showing the first surface side (before laser processing) of the insulating sheet according to the embodiment of the present disclosure; FIG. 4 is a front view showing the first surface side (after laser processing) of the insulating sheet according to the embodiment of the present disclosure; Front view showing the first surface side (before double-sided tape is attached) of the insulating sheet according to the embodiment of the present disclosure Front view showing the second surface side (before protective film is attached) of the insulating sheet according to the embodiment of the present disclosure Front view showing the second surface side of the insulating sheet according to the embodiment of the present disclosure (after attaching the protective film) FIG. 4 is a front view showing electrodes provided on the second surface of the insulating sheet according to the embodiment of the present disclosure;

A sheet heating element 100 according to an embodiment of the present disclosure will be described below with reference to FIGS. 1 to 7. FIG. In addition, the same code|symbol is attached|subjected about the component which is common in each figure, and those description is abbreviate|omitted suitably.

FIG. 1 is an exploded perspective view of a sheet heating element 100. FIG.

As shown in FIG. 1, the planar heating element 100 has a double-sided tape 1, electrodes 2 and 3, an insulating sheet 6, an electrode 7, PTC elements 8 and 9, terminals 10, 11 and 12, and a protective film 13.

A method for processing the first surface of the insulating sheet 6 will be described with reference to FIGS. 2 to 4. FIG.

The first surface of the insulating sheet 6 is, for example, the surface shown in FIG. 1, and is hereinafter simply referred to as the "first surface". Moreover, below, the back surface of the 1st surface of the insulation sheet 6 is called "2nd surface."

2 to 4 are front views showing the first surface side of the insulating sheet 6. FIG. FIG. 2 shows a state before laser processing is performed on the first surface. FIG. 3 shows the state after laser processing is performed on the first surface. FIG. 4 shows the state where the electrodes 2 and 3 shown in FIG. 1 are provided on the first surface shown in FIG. 3 (the state before the double-sided tape 1 shown in FIG. 1 is attached).

The insulating sheet 6 is a sheet-shaped transparent member having electrical insulation. First, as shown in FIG. 2, the entire first surface of the insulating sheet 6 is provided with a transparent electrode A that generates heat when energized.

Next, laser processing, for example, is performed on the transparent electrode A shown in FIG. As a result, grooves 6a, 6b and 6c are formed as shown in FIG. The grooves 6a, 6b, and 6c may be formed by half-cutting using a mold, for example. Known techniques can be used for laser processing and half-cutting using a mold.

The grooves 6a and 6b are provided from the upper end to the lower end of the insulating sheet 6 along the longitudinal direction (short side direction of the insulating sheet 6; the same shall apply hereinafter).

The groove portion 6c is provided from the right end of the insulating sheet 6 to the groove portion 6b along the lateral direction (long side direction of the insulating sheet 6; the same applies hereinafter).

The depth of each of the grooves 6a to 6c is the same as the thickness of the transparent electrode A.

By forming the grooves 6a, 6b, and 6c described above, the transparent electrode A is divided into a first region 21, a second region 22, a third region 23, and a fourth region 24, as shown in FIG.

The first region 21 and the second region 22 are electrically insulated with the groove 6c as a boundary. The first region 21 and the third region 23 are electrically insulated with the groove 6b as a boundary. The second region 22 and the third region 23 are electrically insulated with the groove 6b as a boundary. The third region 23 and the fourth region 24 are electrically insulated with the groove 6a as a boundary.

Next, electrodes 2 and 3 as conductive portions are provided on the first surface shown in FIG. As shown in FIG. 4, the electrodes 2 and 3 are spaced apart from each other.

The electrode 2 (an example of the first electrode) is provided extending in the horizontal direction in the upper portion of the first surface. One end of the electrode 2 is provided on the first region 21 and the other end of the electrode 2 is provided on the third region 23 . A laterally extending portion of the electrode 2 is electrically connected to the third region 23 .

A portion of the electrode 3 (an example of the second electrode) is provided so as to extend in the horizontal direction at the lower end of the first surface, and a portion thereof is provided so as to extend in the vertical direction at the right end portion of the first surface. One end of the electrode 3 is provided on the second region 22 and the other end of the electrode 3 is provided on the third region 23 . A laterally extending portion of the electrode 3 is electrically connected to the third region 23 .

Terminals 10 to 12 shown in FIG. 4 will be described later. 4 indicates the lower end portion of the protective film 13 shown in FIGS. 1 and 6. As shown in FIG.

The double-sided tape 1 shown in FIG. 1 is attached to the first surface of the insulating sheet 6 shown in FIG. 4 so as to cover the entire surface. The double-sided tape 1 is a transparent member having adhesive strength on both sides.

5 and 6 are front views showing the second surface side of the insulating sheet 6. FIG. FIG. 5 shows the state before the protective film 13 shown in FIG. 1 is attached. FIG. 6 shows the state after the protective film 13 shown in FIG. 1 is attached.

As shown in FIG. 5, an electrode 7 as a conductive portion and PTC (Positive Temperature Coefficient) elements 8 and 9 as a current control portion are provided on the upper portion of the second surface side of the insulating sheet 6. . Note that the PTC element may be called a PTC resistor.

The shape of the electrode 7 is shown in FIG. As shown in FIG. 7, the electrode 7 has comb-shaped portions 14 and 15 and end portions 16 and 17 .

A PTC element 8 is provided in the comb-shaped portion 14, and a PTC element 9 is provided in the comb-shaped portion 15 (see FIG. 5).

The PTC elements 8 and 9 are provided on the back side of the transparent electrode A (specifically, the third region 23) shown in FIG. That is, it can be said that the PTC elements 8 and 9 are provided on the second surface so as to correspond to the position of the transparent electrode A (specifically, the third region 23) on the first surface.

A terminal 10 is attached to the end portion 16, and a terminal 12 is attached to the end portion 17 (see FIG. 5).

The terminals 10 to 12 are conductive members for connecting the first surface side and the second surface side of the insulating sheet 6 .

The terminal 10 is provided through the electrode 7 and the insulating sheet 6 (including the fourth region 24). A lead wire (not shown) is connected to the second surface side of the terminal 10 (see FIGS. 5 and 6).

The terminal 11 is provided through the insulating sheet 6 (including the first region 21 ) and the electrode 2 . The terminal 11 conducts with the electrode 2 (specifically, one end of the electrode 2 located in the first region 21). A lead wire (not shown) is connected to the second surface side of the terminal 11 (see FIGS. 5 and 6).

The terminal 12 is provided through the electrode 7 , the insulating sheet 6 (including the second region 22 ), and the electrode 3 . Electrode 3 (specifically, one end of electrode 3 located in second region 22 ) and electrode 7 (specifically, end 17 shown in FIG. 7 ) are electrically connected via terminal 12 .

Protective film 13 shown in FIG. 1 is attached to the second surface of insulating sheet 6 shown in FIG. 5 so as to cover electrodes 7 and PTC elements 8 and 9 (see FIG. 6).

Protective film 13 is a non-transparent member. The protective film 13 is provided with openings (reference numerals omitted) corresponding to mounting positions of the terminals 10 to 12, respectively. Accordingly, when the protective film 13 is attached to the second surface, the terminals 10 to 12 are exposed from the respective openings as shown in FIG.

The current flow in the planar heating element 100 configured as described above will be described. Here, a case where the current input terminal is the terminal 11 and the current output terminal is the terminal 10 will be described as an example.

A current flowing into the terminal 11 from a lead wire (not shown) connected to the second surface side of the terminal 11 first flows through the first surface side of the insulating sheet 6 . Specifically, the current flows through the electrode 2, the transparent electrode A (specifically, the third region 23), and the electrode 3 in that order in FIG. At this time, the transparent electrode A generates heat. As a result, the object to which the planar heating element 100 is attached (for example, a transparent member of an optical device to be described later) is heated.

The current reaching the first surface side of the terminal 12 then flows through the second surface side of the insulating sheet 6 . Specifically, the current flows through electrode 7, PTC elements 8 and 9, and reaches terminal 10 in FIG. Then, the current flows out to a lead wire (not shown) connected to the second surface side of the terminal 10 .

From such current flow, it can be said that the PTC elements 8 and 9 are connected in series with the transparent electrode A (the third region 23) via the electrode 3, the terminal 12 and the electrode 7. FIG.

It should be noted that the terminals 10 and 11 may be used as the input end and the output end of the current, respectively. In that case, the current flows in the opposite order as described above.

The planar heating element 100 described above is attached to a transparent member of an optical device (for example, a protective glass or the like provided in front of an imaging device) with the double-sided tape 1 shown in FIG. Examples of the optical device include, but are not limited to, an in-vehicle camera that detects the surroundings of the vehicle (can be called a collision prevention camera), a surveillance camera attached to a building, an in-vehicle electronic door mirror, and the like. Note that the planar heating element 100 may be attached to a transparent member (for example, a glass window of a vehicle, etc.) other than the optical device.

As described above, the planar heating element 100 of the present embodiment includes the insulating sheet 6 having the first surface provided with the transparent electrode A that generates heat when energized, and It has PTC elements 8 and 9 connected in series with the transparent electrode A, and electrodes 2 and 3 provided on the transparent electrode A and spaced apart from each other, and the transparent electrode A has the same depth as its thickness. It includes a first region 21, a second region 22, and a third region 23 that are electrically insulated bordering on the grooves 6a to 6c having a depth, one end of the electrode 2 is provided in the first region 21, and the electrode 2 The other end is provided in the third region 23 , one end of the electrode 3 is provided in the second region 22 , and the other end of the electrode 3 is provided in the third region 23 .

Thereby, the temperature of the transparent electrode A provided on the first surface of the insulating sheet 6 can be controlled by the PTC elements 8 and 9 provided on the second surface of the insulating sheet 6 . That is, the planar heating element 100 does not need to control the temperature of the transparent electrode A using an external control device (eg, thermistor, thermostat, etc.). temperature control in can be more easily realized.

Further, in the planar heating element 100 of the present embodiment, the PTC elements 8 and 9 are provided on the second surface so as to correspond to the position of the transparent electrode A (for example, the third region 23) on the first surface. It is characterized by As a result, the temperature of the transparent electrode A (for example, the third region 23) is quickly transferred to the PTC elements 8 and 9, so that the temperature control of the transparent electrode A can be realized with higher accuracy.

It should be noted that the present disclosure is not limited to the description of the above embodiments, and various modifications are possible without departing from the scope of the present disclosure.

In the embodiment, the case where two PTC elements 8 and 9 are provided has been described as an example, but the number of PTC elements may be one, or three or more. It is more preferable to provide a plurality of PTC elements because stable temperature control can be achieved.

Further, the shape and size of each component included in the planar heating element 100 are not limited to those illustrated.

The planar heating element of the present disclosure is useful for a planar heating element having a transparent electrode, an optical device, and a method for manufacturing a planar heating element.

REFERENCE SIGNS LIST 1 double-sided tape 2, 3, 7 electrode 6 insulating sheet 6a, 6b, 6c groove 8, 9 PTC element 10, 11, 12 terminal 13 protective film 14, 15 comb tooth-shaped portion 16, 17 end 21 first region 22 second 2nd region 23 3rd region 24 4th region 100 Sheet heating element A Transparent electrode

Claims (6)

an insulating sheet having a first surface provided with a transparent electrode that generates heat when energized;
A PTC (Positive Temperature Coefficient) element provided on the second surface that is the back surface of the first surface and connected in series with the transparent electrode;
a first electrode and a second electrode spaced apart from each other on the transparent electrode;
The transparent electrode includes a first region, a second region, and a third region that are electrically insulated with a groove having the same depth as the thickness of the transparent electrode as a boundary, and
one end of the first electrode is provided in the first region, the other end of the first electrode is provided in the third region;
One end of the second electrode is provided in the second region, and the other end of the second electrode is provided in the third region,
Planar heating element. The transparent electrode and the PTC element are connected via a terminal provided through the insulating sheet,
The planar heating element according to claim 1. The PTC element is provided on the second surface so as to correspond to the position of the third region on the first surface,
The planar heating element according to claim 1 or 2. The groove is
Formed by laser processing or half-cut using a mold,
The planar heating element according to any one of claims 1 to 3. An optical device comprising the planar heating element according to any one of claims 1 to 4. A transparent electrode that generates heat when energized is provided on the first surface of the insulating sheet,
A PTC (Positive Temperature Coefficient) element is provided on the second surface, which is the back surface of the first surface, and the PTC element and the transparent electrode are connected in series,
forming a groove having a depth equal to the thickness of the transparent electrode in the transparent electrode to form a first region, a second region, and a third region that are electrically insulated with the groove as a boundary;
providing a first electrode and a second electrode spaced apart from each other on the transparent electrode;
one end of the first electrode is provided in the first region and the other end of the first electrode is provided in the third region;
one end of the second electrode is provided in the second region, and the other end of the second electrode is provided in the third region;
A method for manufacturing a planar heating element.

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