heater

Abstract

To provide a heater that does not require image processing on the sensor side, does not obstruct the driver's view, does not consume a lot of power, can maintain an appropriate heating temperature, does not cause temperature unevenness, and can heat up quickly. [Solution] A heater comprising a transparent film, a transparent conductive film formed on the film that generates heat when electricity is passed through it, and wiring that supplies power to the transparent conductive film.

Description

[Technical Field]

[0001] The present disclosure relates to a heater, and further relates to a glass assembly including the heater and a vehicle including the glass assembly. [Background Art]

[0002] Conventionally, heaters provided on window glass of vehicles are mainly used for the purpose of removing frost and ice and preventing fogging. These heaters are generally of the resistance heating type, which generate heat by passing an electric current through a conductive pattern provided on the glass surface, raise the temperature of the glass to melt frost and ice, and remove and / or prevent fogging. (Patent Document 1, Patent Document 2)

[0003] Further, in Patent Documents 1 and 2, sensors such as cameras and radar devices are provided on the inner side (vehicle compartment side) of the window glass of a vehicle, and obstacles or the like around the vehicle are detected to perform control of the vehicle. At this time, a heater is provided in the range of the angle of view of the sensor on the window glass to remove frost and ice, prevent fogging, etc., thereby improving the detection accuracy of the sensor. [Prior Art Documents] [Patent Documents]

[0004] [Patent Document 1] Japanese Unexamined Patent Publication No. 2023-6653 [Patent Document 2] Japanese Unexamined Patent Publication No. 2021-147243 [Summary of the Invention] [Problem to be Solved by the Invention]

[0005] Conventional resistance-type heaters have a problem in that the wiring is located within the area of ​​the window glass being heated, i.e., within the sensor's field of view. This necessitates additional image processing on the sensor side, such as ignoring the wiring, on the camera or radar side. Furthermore, the visible wiring pattern on the glass surface impairs the driver's visibility. In addition, resistance-type heaters cause temperature unevenness near and between the wiring pattern, which can slow down de-icing on the outside of the window glass. Moreover, the wiring pattern can form outside the field of view, heating unnecessary areas and increasing power consumption. In the case of laminated glass, heating both panes of glass from the inside to remove frost and ice from the outside of the window glass takes time to de-ic the outside of the windshield, resulting in increased power consumption. Furthermore, ECU control is required to prevent the heater temperature from becoming too high, necessitating the installation of a separate fail-safe function.

[0006] This disclosure aims to resolve the problems of the prior art described above and to provide a heater that does not require image processing on the sensor side, does not obstruct the driver's view, does not cause temperature unevenness, does not consume a large amount of power, can maintain an appropriate heating temperature, and can quickly heat laminated glass. [Means for solving the problem]

[0007] The heater of this disclosure comprises a transparent film, a transparent conductive film formed on the film that generates heat when an electric current is passed through it, and wiring that supplies power to the transparent conductive film. [Effects of the Invention]

[0008] According to the heater of this disclosure, power is supplied to heat a transparent conductive film formed on a transparent film, so there is no wiring pattern as in conventional heaters, and the entire heater is transparent. Also, since the entire transparent conductive film is heated uniformly, there are no temperature variations. When this heater is installed sandwiched between laminated glass and applied to vehicle windows, there is no need for image processing on the sensor side installed on the inside of the window glass, so the driver's view is not obstructed, power consumption is not high, an appropriate heating temperature can be maintained, there are no temperature variations, and the window glass can be heated quickly to remove frost and ice, and to prevent fogging. [Brief explanation of the drawing]

[0009] [Figure 1] This is a schematic diagram of the heater. [Figure 2] This is a diagram showing a cross-section of a glass assembly including a heater. [Figure 3] This is a diagram showing a manufacturing apparatus for glass assemblies. [Figure 4] This is a front view of a vehicle window glass assembly. [Figure 5] This is a side view of a vehicle window glass assembly. [Figure 6] This is a photograph of a window glass assembly with a heater film. [Figure 7] This is a photograph of a window glass assembly with a heater film. [Modes for carrying out the invention]

[0010] The embodiments of this disclosure will be described below with reference to the drawings. The embodiments described below are all specific examples of this disclosure. Therefore, the components, their arrangement positions, and connection configurations shown in the following embodiments are examples and are not intended to limit this disclosure. Furthermore, components in the following embodiments that are not described in an independent claim will be described as optional components.

[0011] Furthermore, each figure is a schematic diagram and not necessarily a strictly accurate representation. Note that in each figure, substantially identical components are denoted by the same reference numerals, and redundant explanations may be omitted or simplified.

[0012] Figure 1 is a schematic diagram showing an embodiment of the heater of the present disclosure. The heater 1 has a transparent film 2, a transparent conductive film 3 formed on the surface of the film 2, and a pair of wires 4, 4' that supply power to the transparent conductive film 3. The film 2 is formed from a transparent resin that supports the transparent conductive film 3 and the wires 4, 4' and serves as the substrate for the heater 1, and can be formed from a transparent film such as a cellulose triacetate film (TAC film). The film 2 has a main body portion 21 on which the transparent conductive film is formed, and an extension portion 22 extending from the main body portion 21. The main body portion 21 is formed according to the shape and size of the object to be heated, and is formed, for example, in a rectangular shape. The extension portion 22 is formed according to the mounting structure of the heater 1 to the object to be heated and the connection structure to the power supply, and is formed, for example, in a long strip shape substantially perpendicular to the long side of the main body portion 21.

[0013] The transparent conductive film 3 is a transparent thin film formed on the surface of the main body portion 21 of the film 2, which generates heat when an electric current is passed through it. It can be formed by applying a paste containing conductive materials such as silver nanoparticles, indium tin oxide (ITO), carbon nanotubes (CNT), and polyethylene dioxythiophene (PEDOT) onto the main body portion 21. The transparent conductive film 3 is formed in a roughly rectangular shape to match the shape of the main body portion 21. The thickness of the transparent conductive film 3 is formed as a thin film of, for example, 100 nm or less, depending on the power supply voltage, heating temperature, etc. The transparent conductive film 3 is not limited to any material that has the property of generating heat when an electric current is applied, but it is desirable that it contains conductive materials such as silver nanoparticles, ITO, CNT, and PEDOT, which have high transparency and can be formed as a thin film.

[0014] Wirings 4 and 4' are formed in pairs on the surface of the film 2 to allow current to flow through the transparent conductive film 3. These are formed by printing a paste containing, for example, silver nanoparticles or copper nanoparticles onto the film 2. Wirings 4 and 4' have power supply sections 41 and 41' formed along a pair of opposing sides of the transparent conductive film 3, extended wiring sections 42 and 42' connected to the power supply sections 41 and 41' and formed on the surface of the extended section 22, and connection sections 43 and 43' formed at the ends of the extended wiring sections 42 and 42' and connected to wiring supplied from a power source (not shown). One end of the pair of wirings 4 and 4' is connected to the positive electrode of the power source and the other end is connected to the negative electrode. As a result, current flows almost uniformly across the entire transparent conductive film 3 from one power supply section 41 and 41' to the other power supply section 41 and 41', causing the transparent conductive film 3 to heat up almost uniformly across its entire surface.

[0015] Positive Temperature Coefficient (PTC) thermistors 5 and 5' may be provided in the extended wiring sections 42 and 42' to adjust the current supplied to the transparent conductive film 3 and thereby control the heating temperature. PTC thermistors 5 and 5' generate heat when current flows through them, and their electrical resistance increases rapidly when a predetermined temperature is reached. Therefore, by appropriately selecting PTC thermistors 5 and 5' according to the application of the heater, it becomes possible to appropriately control the heater temperature.

[0016] Next, the operation of heater 1 will be explained. When one of the connection parts 43 and 43' is connected to the positive (+) terminal of the power supply and the other to the negative (-) terminal, a voltage is applied between the power supply parts 41 and 41', and therefore a voltage is applied between the opposite sides of the transparent conductive film 3 (the top and bottom sides in Figure 1). As a result, current flows almost uniformly across the width of the transparent conductive film 3 between the power supply parts 41 and 41' in the vertical direction in Figure 1, and the transparent conductive film 3 heats up almost uniformly throughout.

[0017] Further, a current flows through the transparent conductive film 3 to generate heat, and at the same time, a current also flows through the PTC thermistors 5, 5' to generate heat. When an excessive voltage is applied between the connecting portions 43, 43' and the PTC thermistors 5, 5' are heated to a temperature equal to or higher than a predetermined temperature, the electrical resistance of the PTC thermistors 5, 5' increases sharply, so that the current value flowing through the PTC thermistors 5, 5' is limited, and accordingly the current value flowing through the transparent conductive film 3 is also limited. Therefore, further temperature rise of the transparent conductive film 3 is suppressed, and the temperature is controlled to an appropriate temperature.

[0018] Fig. 2 is a cross-sectional view of a glass assembly 100 when the heater 1 of the present disclosure is applied to heating glass such as a vehicle window glass. The glass assembly 100 includes a pair of tempered glasses 61, 62, a pair of polyvinyl butyral (PVB) layers 71, 72 for bonding the pair of tempered glasses 61, 62 and clamping the heater 1, and the heater 1 sandwiched and bonded between the pair of PVB layers 71, 72. The heater 1 may have substantially the same size as the tempered glasses 61, 62 so as to heat the entire tempered glasses 61, 62, or may be smaller than the tempered glass 6 so as to heat a part of the tempered glasses 61, 62. In Fig. 2, the heater 1 is smaller than the tempered glass 6, and the entire heater 1 is covered by the first PVB layer 71 and the second PVB layer 72. In a region outside the heater 1, the first PVB layer 71 and the second PVB layer 72 are directly bonded to each other.

[0019] The heater 1 includes a film 2, the transparent conductive film 3 formed on the surface of the film 2, and power feeding portions 41, 41' of a pair of wires 4, 4' that supply power to the transparent conductive film 3, whereby unevenness is formed on the surface (the upper surface in Fig. 2) of the heater 1. Since the second PVB layer 72 located between the heater 1 and the tempered glass 62 is in close contact with the uneven shape, the gap between the pair of tempered glasses 61, 62 is bonded substantially uniformly throughout the entire region.

[0020] Figure 3 shows an example of a manufacturing method and manufacturing apparatus for the glass assembly 100 of the present disclosure. The manufacturing apparatus 300 includes a hot plate 301 on which the material 100' of the glass assembly 100 is placed and heated, a flat plate 302 that clamps and pressurizes the material 100' together with the hot plate 301, and a chamber 303 surrounding the hot plate 301 and the flat plate 302. The material 100' is made by sequentially laminating a first tempered glass 61, a first PVB layer 71, a heater 1, a second PVB layer 72, and a second tempered glass 62.

[0021] In the first step of manufacturing the glass assembly 100, the material 100' is placed on a hot plate 301 heated to approximately 150°C, and the material 100' is clamped by pressing down from above with a flat plate 302. Next, in the second step, the chamber 303 is evacuated using a vacuum pump (not shown) and maintained for approximately 1 minute to ensure that each layer of the material 100' is tightly bonded. Then, in the third step, the flat plate 302 is pressurized at 0.1 MPa for 5 minutes using a pressurizing device (not shown). Through these steps, a glass assembly 100 can be manufactured in which a heater 1 is sandwiched between a pair of tempered glass panels 61 and 62.

[0022] Figure 4 is a front view of the glass assembly 100 of this disclosure when applied to the front windshield 200 of a vehicle, and Figure 5 is a side view of the same. The glass assembly 100 is installed in the front of the vehicle body (front of the passenger compartment), which is not shown. A heater 1 is fitted between a first tempered glass 61 and a second tempered glass 62 in the glass assembly 100. The heater 1 has a main body 21 of a film 2 on which a transparent conductive film 3 is formed, sandwiched between the first tempered glass 61 and the second tempered glass 62, with an extension 22 extending upward. The extension 22 is exposed from the upper ends of the first tempered glass 61 and the second tempered glass 62, and is bent and joined so as to wrap around to the back surface (bottom surface in Figure 5) of the second tempered glass 62. A connection part 43 for a PTC thermistor 5 and wiring 4 is located in the bent part, and wiring leading to a power supply (not shown) is connected to the connection part 43. Note that the wiring 4 is not shown in Figures 4 and 5.

[0023] Sensors S, such as a camera or LiDAR, are mounted on the back surface of the glass assembly 100 via a bracket 9 to detect obstacles in front of the vehicle. The field of view A, in which the sensors S can detect obstacles, is directed outwards through the glass assembly 100. At this time, the transparent conductive film 3 of the heater 1 is positioned to overlap with the field of view A (see also Figure 1).

[0024] Figures 6 and 7 are photographs of a glass assembly 100 in which a film 2 smaller than the tempered glass 61 and 62 is bonded between a pair of tempered glass 61 and 62 via a pair of PVB layers. Figure 6 is a photograph of the glass assembly 100 in which TAC film is used as the material for the film 2, and Figure 7 is a photograph of the glass assembly 100 in which PET film is used as the material for the film 2.

[0025] In Figure 6, the edge of the film 2 attached to the tempered glass 6 is not visible, and the tempered glass 6 and the film 2 are indistinguishable visually, but in Figure 7, the edge 23 of the film 2 is visible. Generally, the refractive index of TAC film is, for example, around 1.47 to 1.49, and the transmittance of visible light is 92% or more. In contrast, the refractive index of PET film is around 1.58. The PVB layer also has a visible light transmittance of around 92%, which is equivalent to that of TAC film. Tempered glass has a refractive index of around 1.5. Therefore, when TAC film is used, the transmittance is approximately the same as that of the adjacent PVB layer, so the edge of the TAC film becomes inconspicuous, but when PET film is used, the difference in transmittance with the PVB layer makes the edge 23 noticeable. Furthermore, since the refractive indices of the TAC film, PVB layer, and tempered glass are approximately the same, there is little distortion of the external conditions acquired through the glass assembly 100, so the driver does not perceive any discomfort with the outside scenery, and the sensor S can acquire the external conditions with high accuracy.

[0026] Next, the operation of the heater 1 provided in the glass assembly 100 of this disclosure will be described. When power is supplied to the transparent conductive film 3, the transparent conductive film 3 generates heat and heats the tempered glass 6. At this time, since the heater 1 is sandwiched between the first tempered glass 61 and the second tempered glass 62, the distance from the transparent conductive film 3 to the surfaces of the first tempered glass 61 and the second tempered glass 62 is the length of one glass pane. Therefore, the surface of the tempered glass is heated quickly by the heater 1, condensation and freezing can be efficiently removed, and obstacles and other objects can be detected accurately by the sensor S.

[0027] Furthermore, since the heater 1 does not have conventional wiring patterns, the wiring patterns do not exist within the field of view of the sensor S and do not interfere with it. Therefore, there is no need to remove information about the wiring patterns from the information acquired by the sensor S, and obstacles can be detected more appropriately. In addition, the absence of wiring patterns does not visually obstruct the driver, improving the aesthetics. Moreover, if TAC film is used for film 2, the transmittance of the PVB layer and film 2 are almost the same, so the edges 23 of film 2 become less noticeable, improving the aesthetics and reducing the impact on the detection accuracy of the sensor S.

[0028] Furthermore, since there is no need to run the wiring pattern through the window glass, only the necessary parts can be heated, reducing power consumption, and the transparent conductive film 3 can be heated uniformly without temperature unevenness. In addition, by providing a PTC thermistor 5 in the wiring 4, the transparent conductive film 3 can be heated to an appropriate temperature.

[0029] In the above embodiment, the external shape of the bracket 9 to which the sensor S is attached is approximately the same as, or slightly larger than, the main body portion 21 of the film 2 of the heater 1. The bracket 9 is mounted in a position that overlaps with the main body portion 21 when viewed from inside the vehicle. As a result, the heater 1 is hidden by the bracket 9 from the driver's perspective inside the vehicle, so the heater 1, including the wiring 4, is not visible, improving the aesthetics. [Industrial applicability]

[0030] It can be effectively applied to heating vehicle windows, etc. [Explanation of symbols]

[0031] 1 Heater 2 films 21 Main body 22 Extension 3 Transparent conductive film 4 Wiring 41 Power supply section 42 Extended wiring section 43 Connection part 5 PTC Thermistors 6 Tempered glass 61 First tempered glass 62 Second tempered glass 7 PVB layer 71. First PVB layer 72 Second PVB layer 9 brackets 100 glass assemblies 200 Front windshield S sensor A field of view area

Claims

1. A transparent film and A transparent conductive film formed on the aforementioned film, which generates heat when an electric current is passed through it, Wiring that supplies power to the transparent conductive film, A heater having a heater.

2. The aforementioned film is a TAC film. The heater according to claim 1.

3. A PTC thermistor is provided in the aforementioned wiring. The heater according to claim 1.

4. A heater according to claim 1 or 2, A pair of transparent tempered glass panels that sandwich the heater, A glass assembly having a glass body.

5. The heater described in claim 2, A pair of transparent tempered glass panels that sandwich the heater, It has, The refractive index of the TAC film and the refractive index of the tempered glass are approximately the same. Glass assembly.

6. A PVB layer is provided between the pair of tempered glass and the heater. The glass assembly described in claim 5.

7. The transmittance of the TAC film and the transmittance of the PVB layer are approximately the same. The glass assembly according to claim 6.

8. The glass assembly described in claim 7, A sensor provided opposite the transparent conductive film for detecting the surrounding conditions, A vehicle that possesses the following characteristics.

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